For wildlife the 7D would be my choice but for people I'd go for a 1DsmkII every day of the week. If there was any way you could get the 1D by selling the 40D instead of the 7D it would be a no brainer. The 1DsmkII may well be an old camera but that doesn't stop it from being an extremely good one. It does have some issues (terrible screen, relatively slow right speed and high ISO performance is not as good as more modern models, but still not bad), but the AF is superb and the image quality is the best of all of the DSLRs that I have shot with.