Its always fun to do it yourself, I only broke one stud lucky in my case but 4 others just came out of there sockets so i still replaced them, usually the ones that brake are either ends of the manifold 3 near cyl 1 and 3 near cyl 6 WD40 always helps, and where are you located?? Also it shouldnt hurt much if you drive it around with just the one broken, just poor power and no boost if its leaking.
Also ring up your mobile thread tech that are able to drive to your house and remove it for you for a quote on "x" number of studs, Unless you have access to a right angle drill, air compressor and easy outs as these things come in handy when doing something like removing studs, Or 12v drill, stud tap, and easy outs will also do the job, but there isn't too much room either end of the manifold. You will guage what i mean when you do it yourself.
Oh dont forget to clean those metal filings away either they can be nasty. And get the tools and bits n pieces before you start it makes it alot easier as well.
The gasket, you can locate an aftermarket one for less than 100 give repco a call they may help you here.
You get many things from doing these yourself, Experience and knowledge of repair giving a sense of self achievement and also money saving.
Cheers
A