** The Enforcer **
Button head cap screw would be my preference. Socket head cap screw would also suffice.I am going with 18-8 from McMaster-Carr. They usually have pretty good quality. Of course I could go with ARP at about $4 per fastener...The only drawback with the ARP fasteners is that they are only available in flanged 10mm hex head rather than allen head. I prefer the esthetics of socket head rather than hex. What's your opinion?