With current prices of donor transmissions being $7,500+, cost will be $15,000 to $25,000 if you pay someone to do it for you. ATR Parts in Austria sells swap kits with all the necessary parts. To do a complete swap you need to swap your AT cams for manual cams. Otherwise, you'll need to run on the AT ECU and be limited to 7,500 rpm/250hp.
There are probably about a dozen guys in the states who can do this job competently. Where are you located?