Supra head gaskets?

[MA61ME]

What is the story with supra head gaskets in particular mine (MA61-5ME). When I bought it the engine had been reconditioned 20,000 km ago. three weeks later the H/G went, so had it fixed and head machined and done up 500 kms and retorque did all the right things. again H/G blows. Back to shop perhaps gaskets fault, arguments with supplier. another gasket in, not long later it's gone again.
So---- I have looked at many supra sights and all have this recuring mention of H/G problems. Is a metal gasket the cure because I am sick of throwing good money after bad.
At this stage I am considering a 3.8 GM V6 (but I think that might be to tall to fit) or a Nissan RB30, both of which seem to be reliable and with good power. I love my MA61 complete with new $7000 new paint job. I don't want to go the small cubes high tech way and The Toyo 6's obviously have a problem. I would put a V8 in it but to much front weight I think.
When I had the head done I got a cam grind, performance chip and porting $$$$$ down the toilet. and everyone says "Gee that shouldn't happen" . From what I've seen at your site perhaps meticulous perfect finish on block and head and special or metal H/g [B]might fix it. I think I need more certainty or I'll go the hybrid route. Any ideas guys/girls. I'm in Australia by the way.