ARP's are the only way to go... *are there any other brands?*
Cometic is a great mhg, and the tolerances are pretty lienant... They can take alot of boost and hp too... I believe Louis over at Paradise Racing is running 40psi on a Cometic... I used a Cometic in my last supra, and it worked great!
This Supra I have now has an HKS 2.0mm Stopper MHG, and this one is suppose to be the end all, be all mhg for our cars.. I would hope so, this thing is over 300 bucks, lol... But so far, she's holdin 15 pounds of boost like a CHAMP!