Best thing to do is replace buttons and stick by IL (Industrias Lorenzo) parts, these were the parts that were used in the OG arcade cabinets. Someone else may help you with the shops over in America. But if you are European, I can recommend you
http://www.arcadeshop.de/ . Arcadeshop has to be the best around in the EU, ordered from them quite a few times and never had any problems.
And if you are really serious 'bout modding your arcade stick (dual mods, light mods, etc...), Toodles @
http://godlikecontrols.com/ is the dude to go to. The dude sells everything PCB related at great prices!
