Kon, Celestron make a T-adapter for the C8 that should give the correct back focus distance...
http://www.celestron.com/browse-shop...ain-telescopes
I'd suggest you connect your 1100D to a computer and use EOS utility (that came with your camera) or another tool such as Astrophotography Tool (APT) or Backyard EOS to get around the neck bending problem.
Just a heads-up though, due to field rotation with an alt-azimuth mount you will only be able to take relatively short exposures...unless you're using a wedge, or put your C8 tube on an equatorial mount.