Hey Spectral,
If you use 3mm steam pipe bends like i do with my manifolds they aren't going to crack.
If your heart is set of the stock manifold though (which is known to crack) then the other option i have used is to make an adaptor plate to the head which flips the manifold undise down and gives you a top mount setup. This is the 1st setup i ran in the 3SGTE TA22. Drop me an email off forum and i can send you some pics.
I still suggest you use a decent wall thickness tubular setup and you'll won't have any probs