for spacers, there are a few places selling them on the net, but IMHO your best bet is to find a knowledgable friend in a local machine shop, and discuss it with them, maybe ask around in performance shops if they know who can do that kinda work.
get the wheel measurements, and talk to them for a while, tell them exactly what you want to do and how you want to do it.
i was going to order spacers online, but i found out i can get entire bolt pattern conversion and spacers for less...
4x100 and a 35 offset here i come
itll suck for finding wheels with a lip, but ill be able to finally find wheels in 16 or 17" for less than $150cdn a corner, maybe 100 a corner if i go used.
