Scott,
You will need a T-ring as well as a T-adapter. The T-ring attaches to the camera in lieu of the lens, and the T-adapter attaches to the T-ring. It is the adapter which fits into the focuser of the scope. The size of the adapter and T-ring will depend on the size of your focuser - 1.25" or 2".
Now quality wise - you will get what you pay for. Canon make their own, so they are good quality and fit pretty good, but are not the cheapest. See bintel site:
http://www.bintel.com.au/Astrophotog...8/catmenu.aspx
Lots of other makes on the market, so have a good look around first.
By the way - this will probably be the cheapest items you will purchase once you start on the astrophotography path.
Clear skies
Rod
