You don't need to buy anything extra. I put my upr on about 6 months ago and everything that came with the pipe was all I needed. I don't believe it came with manifold bolt replacements so I just used the stock ones. But it did come with the bolts for the two catback connections and the connecting part in the middle of the x itself. Besides a socket wrench you should have a foot long extender and a swivle socket for the manifold bolts to make things easier. Besides that you should be good to go.
Oh yeah, I'd also recommend some O2 extenders for the front O2 sensors. You'll see that the distance between them on the upr is further back than on the stock H. What a pain in the butt that was.
Later
you can get a new passengers side manifold gasket from ford, it's like 8 bucks, well worth it too not get any leaks. the bolts that come with the x pipe for the cat back connection are really good i changed my cat back today and i put my x pipe on 7 months ago no rust on the bolts it was like i put the x pipe on yesterday.
Get Napa part number 600-1819 I believe is the number. Its new driver side manifold studs without the shoulders. Also get a new gasket from ford. Oh and PB Blaster is AMAZING STUFF. Get some, and buy a six pack, cause the midpipe on our cars can be a bear.