no, the D series would not give you more HP for a cheaper price..

Auto is fine.. you can learn to use it just as well...

A D would be cheap and easy , a B20 is known for cylinder walls as thin as woah if your gonna boost, a B16 is high revving, fun engine... really not much to complain about there except new motor mounts, and b18's are fun ...

I mean its all your decision, I would do a D16 if I were to do it again.

and whoever said the Y8 or Z6..

yes..