How to replace a head gasket
 

Can anyone that has replaced the head gasket give me some pointers and also the "new" torque specs to reduce the chances of it blowing again.

Also, whats the cost to complete the repair.

Read through the MK3 FAQ section at the top of the MK3 section and this should help:

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/

I would get arp head bolts at the min and I believe the spec is 75ft lbs

If you don't find some details you're looking for there. I can hopefully help you with any extra questions.

A common mistake I have watched two people make is make sure when it's all put back together and head studs are torqued to spec (I did at 75 pounds)
make sure you set the timing by turning the crank pulley so that the #1 cylinder is at TDC (top dead center) on the compression stroke
and then set the correct timing on your cam gears.......Also after everything is finished before you run the wires to your spark plugs crank your engine over for a couple minutes so you pump the oil and coolent through out your engine and turbo