You may be as well off using the standard one tbh, you need to make a lot of alterations in there so see how it goes. If you have a plastic manifold any more than 5 or 6 psi could rip it to bits tho, but standard engine internals may not like a lot more.
There is a guy called Sev who makes alloy custom parts near to me, he makes intercoolers, manifolds, what ever you want really, if you get stuck he could make a manifold to fit.