I just put Ichiba spacers (10mm Front, 12mm Rear) on my stock SRT rims.
I had to as I put 235/40/18 Nitto Invos on the front. They were not rubbing but they were very, very close to the upper A Arm nut. The tire more than likely would have made contact during high speed cornering.

To answer your question, I paid $85/set for the Ichibas. They are Hubcentric and I have not noticed any vibration from them in the 200 miles that I have put on them. The were an exact fit for the rims - no play whatsoever.

Good luck finding H&R or Eibachs - I tried and it seemed that the 10mm were all on backorder for a month. The 12mm or 15mm seemed to be available however.

Don't run non-hubcentric spacers.

Also don't forget to order longer lug bolts or convert to studs if you are going to be racing regularly. I have heard it is easier when taking the wheel on and off a lot.

Later,
KrzyFast