RE: Doing some upgrades...
I really like the QAD HD Ultra rest. A guy (Scottie/PA) on AT sells them for $90 shipped. For the stab I like the Fuse and for a sight I just picked up the Sword Twilight Hunter from Scottie as well. Seems like a great sight for the money.
As for stings you will not find anything better the John (BuckNasty). I have purchased 15 sets for all my bows, family and some of my friends. He is a stand up guy with great quality and prices.