Contact Raceware Hardware they will tell you what size stud and what to tork them to.
For studs you have two options, raceware and arp. Both are good. Matter of choice. 11mm or 12mm is based off your current bolt size on your head/ block. If you live in Canada you should be able to get the AAZ hg no problem, you can get them in the US but it takes a bit more effort. Myke_w here on the forum sells them. Sizes / thickness is the same as long as it's hydo. Add your location to your profile, it helps local members help you out.