Hi Brad,
Where did the gasket blow, between cylinders or into a water jacket? I assume the head was surfaced when it was reco'd. Is the block flat, run the edge of a steel ruler across the x and y axis and see what feeler gauges you can get under it.
Try giving Minisport in SA a call and ask what head gasket they use for racing, they will have one made out of some super unobtainable material that you need a hazmat suit just to be in the same room with but they should also be able to recommend the next best thing.
Cheers