I paid $2600 at Schramm's for my 6.0. I heard of someone getting a 5.3+trans+t-case from them for $1600 but it sounds way too low to me.
I had no problem fitting my intake under my jeep hood. I used basically the same motor mount locations as the 2 previous SBC's that were in the jeep but I did have to change the design. This put the stock pan too deep. Sure, it looks good for general clearance but I have scraped my low profile corvette pan on rocks. It basically sits parallel to the trans pan. Both are now covered by a skid plate. Haggar, my C6 pan is basically the same as what was in the GTO.
I had Jim's performance do my wiring harness and reprogram the ECM. While doing that, I had him remove the speed sensor. I didn't care. Now, there is a possible down side to that. There are times where I drop from throttle down to idle really fast and it occasionally stalls. (maybe once per 8 hour day of wheeling) Jim tells me that is because there is no speed sensor and the computer can't monitor a relationship between rpm and speed. Never really been a problem though.
I have dual 2 1/2" exhaust all the way back. Not 2 into one. I didn't want to have to screw with a crossover when pulling trans or t-case.