VG,
I would start out with the following items from Brownells.
Colt SAA Screwdriver set - part #080-000-021 $16.70
Wolff reduced power mainspring (hammer) part # 969-322-800 $15.00
Heinie wire trigger/bolt spring - part # 394-630-000 $6.75
Single Action Stoning Kit - part #080-904-000 $59.79
You probably already have a set of good screwdrivers but if not, get them before you do anything.
My USFA's haven't needed anything more than the two springs that I listed above. Maybe I have just been lucky but none of mine have needed any trigger or bolt timing work.
The stoning kit is pretty handy. The stones are designed to reach up inside the SAA frame to get those hard to reach spots like the hand channel. The kit was designed for Brownells by Eddie Janus of Peacemaker Specialists. Comes with a sheet of instructions written by Janus that is quite informative.
Another good book to look for is
Gunsmithing Guns of the Old West by David R. Chicoine. Retail price is $27.95 but you might be able to find a good, used copy for less on one of the book dealer web sites like
www.abebooks.com.
Good Luck,
CJF