The AMG supercharger found on the Crossfire SRT-6 will fit the non-supercharged V6, however at great expense. Not only do you need an engine wiring harness and ECU, but you will also need to lower the compression ratio, which basically means you will need to tear down the engine, and put the AMG spec. crankshaft, connecting rods and pistons into the engine. The MB supercharger runs a hefty 15 lbs boast.
After getting fare amount of information I am leaning towards Kleemans. Total bolt on with no engine mods, no ECU change , no fuel pump change, no wiring harness change, 7 lbs. boast and still 330 hp. With their chip it is around 350 hp.
Only issue is price. $9,500 plus $1300 for install. They do offer a 1 year warranty and I think when you price out all the above, you may find it a reasonable option. I have more info. on their SC if you would like.
The Xfire is still pretty new and everyone of them is still under warranty. Just wait until the warranties are done. I think Vortech will probably weigh in by then with an affordable unit but so far I still like Kleemanns.
You probably know all this already if you have been reading the forum but I thought I would bring up again. Let us know what you do. Good luck.