round here theres a record shop that deals in mainly underground music(hip hop, ska, punk, rock anything not majourly majourly majourly known) and they sell paint and different types of caps.

as for online

http://www.graffitishop.it/home.asp...CFUVJMAodBwtZ-A

http://www.graphotism.com/shopList2.asp?cat=paint

thats the main 2 i use(mainly the second one)