I think that the gt-500 is the best option, because it already comes with loads of power, prestige, not to mention it is easily upgradeable. In fact i was reading the other day that steeda offers some pretty impressive numbers for the gt-500 for about 1/5 the price of a new supercharger. includes a pulley and cold air intake. If i remember correctly thats like 550 rwhp with a tune, so like 630 hp to the crank. Not a bad option if you ask me. and safe.
"There is no replacement, for cubic displacement"