Best telescope for astronomy I am interested in buying a telescope and I would like to use it to look at like galaxies and nebulas. 

Right now I'm looking at a 130 mm fast (f/5) Newtonian that comes with two eyepieces of 10 and 20 mm focal length. It comes with a tripod and German equatorial mount that includes fine motion controls for both axes. 

This seems about right for what I'd like to do. It's going to be my first telescope and first time to try to look at galaxies and nebulas. 

What are other considerations I should weigh before choosing the final one to purchase? Which features might be most helpful for a beginning observer looking for faint objects?
"Galaxies and nebula" are faint and spread out, and for that very little matters as much as aperture!  Back before light pollution was a a serious problem, 6 inches (150 mm) was generally acceptable, these days I tend to recommend 8" or 10" (200 or 250 mm) to just to get through the sky glow.

The 5" scope you are thinking about will be very nice on the Moon, and Saturn/Jupiter and some larger smudges should be detectable but... the view you'll see of "Galaxies and nebula"  is not likely to knock your socks off.