Fiddy,
Lots of stuff here for Hondas. Monkey Project? Most "custom" guys here are switching to the auto 125 step-through so older Cub stuff is getting less plentifull.
I built a 115cc Wave/Astra in Indonesia. Lots of stuff there as well. Bring lots of dimensional info for "shopping" . Engine stuff Ok, but most Thais simply bolt on shinny bits. Kawasaki Kaze piston with new liner and machining would give 113cc. I did that first. Second version used 54mm piston and conrod (800,000Rp) from JA pan and a big valve head ( 1 million something) both bought in JKT, carburettor (800 baht) and camshaft (1200), aluminium swingarm (1500) , upside down forks (2800 ordered), oil cooler(1500) . exhaust (1500) , fancy ignition coil (300)etc. from here. Easiest shops in BKK are all +/- 100m from Saphan Kuay Skytrain station. I bought my stuff in Rayong south of Pattaya. If gong to Pattaya it is an easy daytrip.
There are also some shops, obviously, in Pattaya, just ask a motorbike taxi guy but Rayong has more technical stuff, I found.
Faddy Bike here specialises in Monkey, but charge European prices,
I think 71-ish for 300 kit. Graph is on TYGA site which you can access as you are "overseas".