Hmm , if you want to mod somethings , do those easy ones first if you are new. For example , changing bearings , wheels , grips , locking your folding mech and all. I ride with ODI LongNecks now. They come with some bar plugs which are good but I don't use it as I have metal ones.
The bads about it is that when your hand sweats , you can't grip as well on it. Probably the same for other grips. I don't know.
Wheels , Yaks which you can buy at the SR store here.
Bearings , Bones Reds seems to be cheap and very good. I don't use it as I have ceramics but most people say its good and cheap.
Locking folding mech , look around at pictures and figure out how. Try not to double post if you can. Edit it.Good luck!