I feel I should mention that it's worth while to check out the Whipple and KB units too. Both are solid. I really think it's a coin toss between the three, if you like the more conservative look of the Saleen, or the more aggressive look of the exposed blower in Whipple and KB.
People say that the Whipple and KB units have a higher overall headroom, but unless you have a built bottom end you won't be able to use it. Supposedly the Saleen runs out of room at 14 PSI, where the other two will head upwards of 18-20 PSI, on the stock bottom end you wont see any of those (at least not for long).
Dan