I'm going with 30mm, I did a lot of searching on the forum, looks like there was some confusion about which style you would get when ordering the H&R spacers. I don't think it matters which style I get, both companies Eibach and H&R are reputable places, so studs or the ones without studs are fine to me.
Hey AlecX5, why did you use longer bolts? Everything I've seen in my two days of reading about this and visiting the manufacturers websites shows that if you have the spacers without studs you reuse your old bolts. Your not actually bolting the wheel to hub on the truck, you're bolting it to the new threaded holes in the spacer. Here's a link to a thread discussion from a few years ago.
http://www.xoutpost.com/bmw-sav-foru...ers-added.html