Another Con for the 24-105mm, the F/4 aperture doesn't let your camera use the high precision AF system. The f/5.6 AF points are accurate to somewhere within the DOF, while the f/2.8 AF points are accurate to within 1/3 of the DOF... and I guess that's 1/3 of the narrower DOF, so even more precise than the immediate implication.

I wouldn't worry too much about a bit of focal length overlap. Indoors you'll might often switch between longer lengths for portraits, and wide lengths for groups, or to include context. It would be painful to switch lenses every time you were taking a slightly different shot.