Oz super magneto motor works $19.99 more winds on the magneto versus stock....
The plug kit I saw on there comes with clutch pads should I buy that kit ngk boot 6hs, 7hs, and 8hs?
Sounds like a good deal for $16.00 but how quick do clutch pads wear out?
Also carburetor upgrades are always good even if not beneficial high quality = less chance of float sticking.
As for expansion chambers what are some good brands under $100.00?
I want one that is fair but not so large it's a "police magnet" even an exhaust that is similar to a dual exhaust or chopper style.
What plug you need should be decided by the temps in your area...With NGK, the lower the number the hotter the plug or maybe opposite I forget..lol
If it's really cold the 6 might be a better choice...something like the 60 70s maybe the 7 and 80s up I'd try the 8...this isn't set in stone but more less showing you how to decide on a plug range.
Clutch shoes have nothing to do with the Magneto....you can buy heavy duty clutch shoes which are nothing more than semi metallic automotive brake pads cut up to fit the big wheel.
Considering your only wanting to hit maybe 35 mph tops I would try the Zeda66 pipe which is only $49.99 and is designed to work with stock to mildly modded engines...it's a true expansion chamber none the less so it's worth a look.
You can get the MZ65 pipe which is in the $80 range and I'm thinking it's more for midrange to top end on a moderately modified engine.
Neither pipe will be perfect for your motor but I feel the zeda66 pipe would give you that low end and midrange you need.
Do some basic and simple cylinder clean up and I think you would be happy even with a stock carb and intake...getting a longer intake would work even better...I'm just going to use a hose to extend my intake length using the aluminum intake.
You can get the Keihin clone 16mm carbs for $20 or less if you really want a bigger carb...just make sure you use the steel intake and not the aluminum one unless you don't mind boring the inlet side out...I have one I bored to 15mm and still have plenty of meat left to get maybe 17mm from it.
Good luck finding the adapter needed however for the bolt on flange with the Keihin clone carbs.