Your best bet is to probably buy a used KA, tear it apart on the bench, rebuild her with decent pistons, and a decent head gasket. You dont need anything crazy for the HG if you have arp studs.

The main reason HG's go out is because the stock studs stretch with the heat and pressure of boost, so when they stretch its less pressure holding the HG down and now its easier for it to be blown out by the high pressure in the cyl.

Arp studs are much stronger and resistant to any stretching, my pal had a CA with stock replacement HG and arp studs and pushed 17 all day long. (then again CA's are little monsters. Midget RB )

To reiterate get a used/blown KA, rebuild it, paint it up nice, gather your parts and build it as you go. For the price of the KA, and a rebuild kit + your thrown together kit, (not much for a KA/rebuild kit) You have an easy cheap yet STRONG and RELIABLE KA-T - If you of course tune it as everyone says. That is key.