well you need to just make sure your head isn't warped etc, do a compression check on the motor before you rip it apart to make sure the rings etc are good... if they show up 142 or more evenly each cylinder then she should be a good bottom end
so...
#1 make sure head isn't warped $30 or something for a machine shop to check it
#2 get a new stock gasket from toyota
#3 get arp head studs torque to arp's specs or 72ft lbs
#4 put in your oil and water/coolant
#5 enjoy your supra for a long time to come
the stock gasket from memory can hold 300rwhp fine... as long as the car is well maintained and not thrashed when cold etc etc.. i'm sure you know this already hehe
if you do the head gasket right, then you shouldn't have a problem
good luck with it
