Which Detector might suit me?

G'day everyone.
I am looking to get a better, more gold specific detector but have some health issues, mostly arthritis in my hands especially the thumbs.
Please do not think I am whinging when I describe my situation but I wish to get the most suitable detector to suit my capacities.
When the arthritis plays up it can affect me from my finger tips to the bottom of my rib cage BUT that is reasonably infrequently & I do have strong medication which, when coupled with appropriate rest, enable me to do a fair bit most of the time though not nearly as much as I used to be able to do.
I still work part time (which I enjoy, partly because I still feel useful & can share my knowledge) & live in an area which has mostly finer gold which is harder for detectors to find so I cannot justify spending a huge amount on a machine. One of the reasons I want the gold specific machine is that we are planning to travel when I retire & detecting features amongst my plans.
I read posts on this Forum which relate how much better 5000's work than 4500's, which I can understand & appreciate but you have to be able to find & access appropriate places to use them.
My current budget is around $2,500 to $2,700. I have been looking at the Minelab GP3,500 sort of area.
My main questions include: how heavy is a 3500 compared to say a 4500 (if I save for a bit longer?)
Do things like harnesses make it considerably easier to swing a 4500?
Is a 3500 still worth swinging considering so many people are now using 5000's & getting the smaller pieces of gold & re-working areas considered flogged before the newer machines came along?
By the same token, I have the opportunity to buy a modified SD 2100 machine, is that worth looking at or is the technology too old to be worth considering?
Most of my current detecting is done with a Minelab Safari which I use for coin shooting & relic hunting but as stated before, would like a more gold orientated machine as well.
I have read replies Forum members give to questions like mine & find posters genuine, helpful & courteous so I will certainly respect the answers I receive.
Cheers, Keith.

G'day Keith.
        After careful reading of your post,I find it a little difficult recommending what would best suit you,for only you know the extent of what your capable physically of,without me feeling some form of guilt down the track of not having recommended the right answer to your question,but here goes.
Your obviously concerned about weight factor,at the same time though you state that the gold in and around your area,consists of being mostly small or fine.If this is the case,and the gold you chase is found in or over shallow ground(0 to 5 inch mark),ground that is of average mineralization but not high,consider the "Fisher Gold Bug 2" coupled to a 6.5 inch coil. It don't matter whether the 2100 is modded or not,as long as it works and works well and that its coupled to the right size coil/combination suitable to the type of ground/type/size gold your chasing,you'll find gold,as long as the golds there,within reach to be found in the first place.Problem with the older machines,is that you'll most likely be lugging around excessive weight via battery/machine/coil combination,as compared to the latter GPX Series/battery/coils.Also(not that I'v asked),Minelab don't or won't service or repair the older model machines especially once modified or electronically tampered with,but you can get in touch with Minelab moderators that do.
A good working GP 3500 was or should I say,still is a formidable opponent to the GPX series,but will struggle with mono coils when working above average mineralized ground,bringing us to the GPX Series detectors,of which all models are one step above in performance from one another and all  are quite capable of handling mineralized ground,far better with mono coils than their predecessors,the GP Series.
The current new Minelab harness,coupled to a Hip Stick & or Easy Swing Arm,should take a lot of stress/weight off the shoulder and distribute it evenly over the entire body,making life,a lot easier to swing the medium sized or larger coils. Hope I'v been of some help to you.  

          Cheers Kon.

Thank you for both your reply & your concern Koni. I must admit, a Fishers detector had not entered my mind but I will take a look at the benefits one offers. I have learned, through uncomfortable experiences, to rest before I get too far beyond my physical limits & unless I get too carried away I should be O.K. there.

Hey Keith, Keep in mind that I didn't detect any gold here until I got the 5000 BUT Nev has a GP Extreme and is still getting gold. Two fellas I have run into when I've been out and about have a Fisher F75 LTD with a 5" coil and gets gold with it. Other guys around here are getting gold with the VLF machines so maybe have a look at a Gold Bug 2 or a Whites GMT. Both can be hip mounted to take the weight off your arms. That said, the terrain here destroys me and I can rarely do more than a few hours before I am buggered then you have to walk out!

Does that mean my Safari has the potential to find gold too?
A Fishers machine is a departure from what appears to be the accepted norm- most in Oz seem to prefer Minelab machines. Is that the case or are they merely the more vocal detectorists?
The Fisher appears to be a relic machine as well as a gold detector, would that mean I would no longer require my Safari as the Fishers can do both?

Just re-read an American magazine which listed detectors for various situations & it recommends the Safari (among others) as a coin & relic machine, not so much for gold. For gold it lists Minelab: GPX5000, Eureka Gold & X-Terra 705; Whites: TDI SL, GMT SL & MXT;
Fisher: Gold Bug PRO & Gold Bug II; Garrett: Infinium LS & AT Gold & Tesoro: Lobo Super Traq. More there to consider so I am looking at forums & You-Tube for more info.
Any feedback on these would be appreciated, cheers, Keith.

Thanks Koni, I ordered a Gold Bug DP today, it seems to tick my boxes.