H&R spacers are not available with built in studs until you get into the 40+mm range AFAIK
Eibach or H&R offer spacers with i assume new studs (i've only seen kits with wheel bolts for euro apps). you will have to remove the stock studs and install the longer ones....sounds like a nice option vs. buying aftermarket wheels, esp if you like your stock wheels.
i made a thread about this a while ago and didn't get much feedback other than people telling me that spacers can be detrimental to the hubs, when in actuality hub centric spacers are no different then getting a different offset wheel. look at all the bazillion guys who auto-x their miatas and hondas with uber bumped out offsets, then put their road wheels on and have no issues forever.