If you're looking for straight DIY bolt-up, you'll probably have to stick with Kooks systems to get their mid pipe bolted up. After the midpipe, you should be able to use any axleback you want. Some pipe trimming may be required for fitment. Beyond that, any reputable exhaust shop can make you a midpipe that will fit any muffler setup you buy, and likely fit better.
Phastek sells a DIY install kit, everything you need to get the LT2 installed properly on a LT1. If you're not looking to DIY, you can send it to GPI to get prepped and/or ported. They also offer TB options. Your adapter needs will depend on the throttle body you decide to go with, but for the LT5 TB just a 95mm to 87mm,
Soler sells one. If you're porting the LT2 snout, you'll need a different adapter.