The 7D is great, and the only issue I really have run into is the crop factor with close wide shots. Plan on getting a nice wide lens. I have also opted for manual focus Nikon lenses all with adapters for the 7D, which have been great. I tend to use a 35-70 mm for interviews to change the shots in between answers.
The cadillac Zacuto Z-Finder is well worth the money.
The only advice I did not heed and wished I had, was to build your kit slowly to see what works best for you. I ended up with some gear that I rarely use (shoulder mount and cage).
David Decker