I acutally just got some spacers for my new wheels coming in. i got some m2tuning.com ones. I orginally ordered Powered By Max but they contacted me and they are 'out of stock' of the size i wanted and wouldnt have more until end of april AND they were 50% more cost because it was going to be a new design.
M2tuning.com has more sizes, and sells hub rings seperate if you want it to hug the hub. I talked with the guy and he was telling me some pro teams that use their spacers, and have used the 50mm bolt ons without the hub rings and it was just fine.
If you go slip on and want longer studs, i believe the nissan quest studs should be the SAME thread, thickness, and lug fitment but are 15mm longer, and still cheap. theoretically, you could run up to a 15mm slip on and have no change in threads locking the lug on.