http://highcountryarchery.net/products/arrows
The HC arrows are substantially lighter and faster than anything else and yet still more than strong enough. I've fired them through plywood with 80-lb bows without damage.
Other best of breed kinds of items would include one of the Scott release/triggers made for string-loops (Silverhorn), a good three point arrow rest, and a good optic fiber adjustible sight:
Scott Silverhorn release:
Imaact-archery single-pin sight: 
Simple 3-point arrow rest, $10 on ebay:
Once you get to hitting a baseball-sized target at 20 - 30 meters, you'll want hunting points on the arrows. My recomendation is the NAP bloodrunner mechanical:
All of that stuff can be had on ebay.
Usable compound bows can be had on ebay for 200 - 400. An example:
http://www.ebay.com/itm/Hoyt-Ruckus-Compound-Bow-/251253223857?pt=LH_DefaultDomain_0&hash=item3a7fdbf1b1
Again for anybody with shoulder problems, a compound bow is the only shot. The compound bows hit substantially harder than traditional bows of the same poundage and that's because peak weight is at middle draw. In other words, a 70-lb compound bow is going to hit like a longbow with 70 lbs at mid draw, which would be a much heavier bow.
