Can you retrofit a GSX fuel tank to your GST? Would be better than the hassle of a surge tank. Anytime you can use factory parts and minimize extra fuel fittings and crap it's mo'betta.

Or, if the tank can be removed easily enough, you could also look into maybe having a baffle welded into it, or a cup around the fuel pickup or something. (obvious precautions about welding and fuel, yadda yadda) All you really need is something to preserve fuel around your pickup for 5-10 seconds.

Depending on how the fuel pump and the fuel pump are situated and mounted in the tank, you might even be able to get creative and make some sort of bolt-in cup or "shroud" as a part of the pump assembly that you could just drop right into the tank.