Project: Lincoln LS Drivetrain

The car is a 2003 Lincoln LS V8, its RWD. It's been wrecked (mostly cosmetic damage).
Alright, I'm going to be doing something that a lot of people consider taboo or just plain insane: I'm going to drop a completely new engine (chevy 305) and tranny (probably a tremec T56 6-speed unless anyone has any better suggestions) into a 2003 Lincoln LS. Yes, It's expensive as hell. Yes, It's a huge pain in the ass, I'm aware of that. I want to do it as a learning experience (never done an engine swap before).

My problem however is with the drivetrain; the parts "behind" the gearbox. Initially I'm going to be upgrading the powerplant from the stock 280hp/286ftlbs jaguar engine to a Chevy running around 400tq, and (much) later, higher than 500+tq. I'm aware that these parts need to be replaced but I'm having difficulty determining exactly what needs to be replaced with what, and more importantly, where to find these parts. Any suggestions?

Ok I realize that that was a pretty vague question, here's some more info:
The engine will probably come out of a GM F-body (Tranny may come with it if i get lucky) such as a camaro. I'm mainly looking at performance remanufacture builds that are producing high 300 to mid 400hp/tq. However I'm wanting to play with forced induction later on so my tolerance threshold is more in the 600hp area, i don't want to put a whole new rear axle in, then have to tear it out again a year later because I didn't plan ahead.

I'm assuming it will need a new Driveshaft, Differential, and Rear axle but I'm having trouble finding "performance parts" that are specifically stated to support the LS. I'm still looking but initial searches on eBay and google didn't turn up much. Since the parts I'm looking at now generally find home in F-body vehicles I was considering looking through these parts for F-body vehicles and seeing if I can get any results that way. Not likely considering the difference in size of these vehicles though.

Also, I know I'm being stupid and missing something else that's crucial. I'm assuming all the necessary bearings and joints will come with the above listed parts (is this correct?). Even if you guys could just list some names of companies who build/modify/remanufacture these parts it would be a big help. Thanks.

Basically, all you need is a custom driveshaft. They aren't too expensive. A driveshaft starts with an output yoke. The front of the shaft also has a yoke. In between those goes a U joint. At the back its the same thing; the end of the driveshaft has a yoke, as does the rear differential. You need to have a driveshaft fabricated that has GM bits at the front, and LS bits at the back. Length will be determined by final installation of the engine/tranny, but the driveshaft is the easy part.

The one hitch you'll probably run into is that I believe the LS has a fixed-CV joint at the differential. Not a huge deal, just a wee hurdle.

I suggest you get the driveshaft stub with the GM tranny, and save your LS driveshaft to use for parts.