What size exhaust tip would I use. I was searching around and got mixed emotions on the size of the exhaust so, what size tip would be the best fit for the 2000 V8 Magnaflow kit?

The Magnaflow exhaust size outlet is 2.25". You will need to get an exhaust tip that will be at least that size for the inlet size. The tip outlet size is your preference.

The Magnaflow exhaust size outlet is 2.25". You will need to get an exhaust tip that will be at least that size for the inlet size.

So I should have a sleeve welded in place to hold them to the tail pipes? I would rather just have something slide over and do it myself but I really want some damn tips on this thing.

Since the Magnaflow system has down turned tips you'll need to cut them off just before the hangers. I'd leave as much of the existing tip as possible and then you can get any type of tips that can either be welded on or slide over the existing piece.