Welcome to the forum!
I upgraded to a 7D a mere four months after starting with an XTi. (400D) I was being mentored by my wife, and was handling and shooting with her work camera, a Nikon D300s, which is the Nikon equivalent, more or less, of the 7D. I do not believe either of these excellent cameras is too much for a beginner. If you have large hands, this is all the more so. The 7D does demand that one be a serious beginner, but is actually quite user-friendly, in mu opinion.
Canon 7D/5D/40D/1D2N; Nikon F6, FM3A, & Coolpix A; Canon 40mm Pancake, 135L, 50L, 35L, pre-II 50mm 1.8, 100mm 2.8L Macro, 10-22mm EF-S, 28-135 EF, 400mm 5.6L; Nikkor 50mm 1.2 AI-S, 50mm 1.4G, 50mm 1.8D, 16mm 2.8D Fisheye, 180mm 2.8D, 100-300mm 5.6 AI-S; Tokina 17mm & 100mm 2.8 Macro