a plethera of questions

[moocow]

Hi everyone, I've been lurking for a while. I'm considering building my own car someday, probably something similar to daytona coupe, though it will probably be of my own design. This is sort of what I'm thinking. I want a daily driver that will go at least a hundred thousand miles without a complete engine rebuild. I'm probably looking for about 300 hp, and I'd like to get as high gas milage as possible given this amount of horse power. I'm not really looking for a race car, just something I can smoke all the ricers with.

Here are my questions...

Would it be more fuel effecient to have a smaller turbocharged engine than a larger non forced induction engine, given the same end hp? Also, in general would it be more fuel effecient to start with a smaller engine and squeeze every last bit of hp out of it to get the hp I want or start with a slightly larger engine and set it up more conservatively.

Would it be completely insane to place an engine in the front and transmission in the rear? Any suggestions? I like a little more over steer but don't want porschesque handling. Sadly I'm also considering a tiptronic (autosick) transmission (I'm lazy).

Any thoughts on all wheel drive?

I'm really just looking for broad generalizations. Assume someone who knows there stuff would build and dial in the engine, and that price isn't an issue. Right now I'm just in the college student dreaming about building a car stage.