Though Ron had some idea of what was going on, I feel he is somewhat uneducated in the area of realism. I would recommend a Canon 800mm f/5.6 for your wide angles. You evidently wouldn't purchase a Canon 15mm for the simple reason that it is incredibly zoomed in and should be exclusively reserved for athletics. I hear that the 800mm f/5.6 pairs great with a Canon XT. Keep in mind that you will need a tripod for the 8mm; after all, it is nearly impossible to handhold at more than 9 pounds.
With all seriousness, go with a T3i and 18-135. You will learn from there!
GW