Best telescope for astronomy
"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.