SS16 ONAN Sears Choices???

I have 4 questions and would appreciate any help.
#1. What is a good place to buy a rebuild kit... for the Walbro Carb on the Twin 16 Onan???1977 SSSears.
#2. What are the best plugs to use? I do not know the stock spec. I have a manual coming.. but, perhaps you know?
#3. Belts? I would like to replace all the belts?? Where can I find the right ones/ where is a good lace to get them? Any part numbers appreciated.
#4. Has anyone tried an electronic ignition removing the solid state successfully?? What and where would you direct me to call?
#5. GAS CAP??? Would anyone have a gas cap for sale???
ANY AND ALL INFO APPRECIATED. I have just parted out my ST16 and am now starting on the SS Onan!

#3It appears-
V-BELT, CENTER TO OUTER MANDRELS 3716R (Gates 6887)
1/2"x87"
V-BELT, MOWER MAIN DRIVE BELT 3555R(also available at Sears)
5/8"x103" (Gates B100)??
main drive sears part #6474h

#4 http://home.earthlink.net/~edstoller/id16.html

#5 http://www.the-partconnection.com/

i have the tractor , mower deck, and dozer manuals .. can try to help you if you still need info'
plugs gap @ .025 167-0241 part number ... sry no conversion chart for modern plugs. points part # 160-1154 gap same when cold wide open ... v belt ground drive 2692r part # .. cautions that this belt is special to this tractor and only use this one .... 6941r main mower belt v belt .... v belt center to outer mandrels 3716r ... if i missed something give me a shout @ jb_davis_tn@yahoo.com .. hope it helps

I have a 1976 ss16 the plugs in mine are champions H10c write or wrong it runs. I just replaced the drive belt a daco L583 which means 5/8'' wide 83'' long nobody had one but a local tractor store had a Daco Bp80 which is about the same thing and it dives my tracor just fine.