DSLR advice needed

[Ivan]

I'm Looking for a good DSLR with the following requirements list

[*]M42 or K-mount adapter available. One of these on the body would be even better.
[*]Mirror casing long enough for a Peleng fisheye with filter in place (goes on the rear!) whitout having to mess around with mirror size
[*]Both full auto and full manual control
[*]Full manual lens support. No messing with tape on lenses and adapter rings

Optionals
[*]Built-in flash
[*]SDHC support... thats 4GB SD cards

Personally i'm thinking either Canon or Pentax...