Although you can get a factory EFI manifold for a L4, they are a bit restrictive in the power department. O.K. for a mild street turbo but if you want some decent power you are better off going for something custom. A member here Sikyne can make whatever you want, I have seen his work and it is very good. Mark from Ozdat has a twin weber manifold that has a custom Sikyne plenum bolted up to it and is a pretty neat setup.