Supercharger kits are in stock at almost any serious performance shop. Most people stick with blowers because the ease of installation and be done with it. A turbo isnt something you can just toss on and call it a day. Kits are currently backordered for 2-4 months by some companies.
The following info was taken from turbomustangs.com.
In this month's MM&FF, there is a shoot out between the stock Cobra blower, a twin screw blower, a centrifugal blower, and a twin turbo kit.
The twins blew all the blowers away, except below something like 3000RPM from the positive displacement blowers. Each were limited to 11psi (though the twin screw blower showed about 13psi on one chart ).
Turbos are hands down a far more effiecient power adder, its just alot more complicated.
Why a supercharger will be around....
1. A few of them are street legal, I know in California and turbo kit get hosed unless you "know" somebody to help you get it past smog and inspection.
2. Superchargers are WAY cheaper to get into, $1700-1800 versus the 3-4000 you would spend on a small turbo kit.
3. Lots of people are afraid... Don't know why but I guess turbos are still an unknown for most.
With the stock shortblock as a limitation they will both end up in pretty much the same place. Granted the turbo will have more power under the curve and be quicker on the track but the ease of install and availability are big plusses to the typical street car.
Joe, intrcptrstng is on his way now to get my kit. 2000 for the whole sc kit and aftercooler, and 250 for my longtubes and h-pipe.
Only at a point where your at, do I see it worth it to go turbo 
Good numnbers
