I don't think it'll fit on a 6sp Crossfire - if you search the forums for "srt6 manual" you'll find the wide variety of attempts to create a car with the AMG engine and manual transmission, and the general result is "too hard" or "too expensive" - they don't mate up perfectly and fabrication of various adapters or the use of one specific crankshaft is necessary.

If that engine comes with an ECU, it's just a matter of "training" it to the VIN and modules in your car - Rudy at Accelerated Industries is the master in this department - it basically involves using the Mercedes diagnostic tools (DAS/Xentry) in developer mode to clear any prior associations the ECU may have, and then letting the ECU learn its new home.

If it doesn't, you'd probably be best starting off with another 32K ECU, although I think the Eurocharged guys might be able to flash 32K ECU code onto a 3.2 N/A ECU now.