If I was planning a turbo build, I'd go L32 (first option) or L67 (second).
Might as well do an aluminum L26 UIM:
BonnevillePRO.com • View topic - L26 aluminum UIM on L36--Done! With results!!
IMO the closer to the cylinder you inject the fuel, the better. But to plug the unused injector holes:
A friend made those for me. I'm sure I could get him to make more. With these, you could keep the holes around and, as was suggested, consider some kind of alky injectors later.
I would keep the n/a LIM, so you still have some runner length and don't lose all your low-end torque.