http://www.4gcivichowto.0catch.com
theres the site I made to show how "hard" it was to do my own catback. I basically took two days because I didn't plan ahead. I had the same problem you have with the cat being fused to the old pipe. I wasted so much time trying to hacksaw those bolts (If I had a dremel at the time, that might have done it), when I justed ended up taking it to my dads friend and he torched the bolts out. after that it was complete bolt up, easy as pie.
Mine came with some hardware, although I had to buy a few extra gaskets and one bolt. oh and also, make sure you put the midpipe in RIGHT SIDE UP! for a week I couldn't figure out why it was scraping on every bump!
just do it yourself, you'll feel great about it!