If you go turbo, make sure you get it mapped to your engine. No sense in taking someone's advice, and going out and getting a super huge turbo that doesn't start making boost until 3500 RPM, or getting to small of a turbo that spools fast but only makes 7 psi max lol. Most manufacturers will already have mapped it out, but it is specific to your set up so get with someone who knows what they're doing. Personally, I'd go supercharger, but that's just me. I'm a twin screw kind of guy, and I don't buy in to the whole efficiency thing. WE DRIVE MUSTANGS. I don't think MPG matters, otherwise what's the point? LOL maybe that's a little ignorant.. anyways, if turbo'd, then get 3.73 to 4.10 gears to make up lag difference. I know people argue that the lag is minimal, but still.. go up against someone with a supercharger who makes immediate power and you'll want those gears, and a six speed tranny lol. Superchargers are much easier all around, and cheaper. Sticking through the hood? You're thinking the old style blower's lol, and I don't like those on anything but an old muscle car. As for some of the newer ones that still sit high, they don't look good IMO sticking through a cut out hood.. if you're going that big anyways, just get a cowl hood. Make sure you have good exhaust for going forced induction. Another thing to take in mind is what elevation are you at? You lose .5 pounds of boost for every 1000 feet above sea level, so superchargers are nice because you can just swap a pulley. I'm at 6000 feet, so I like the supercharger, 6 speed, 3.73 gears, fat tires, equal length ceramic long tube headers, h pipe, and a little nitrous
.. but then again.. we're talking thousands. What do you like more, a whine, quiet, or a whistle? Do you want top end power and high speed, or low end neck snapping torque and instant off the line SUPER acceleration? Depends on your driving style and preferences as well. Turbo's are easier to launch off the line, superchargers are touchy and make lots of tire smoke, so.. just some thoughts. Hope this helps!!