I took a different approach than most (but I am not a serious long-range shooter).

After using a few less expensive spotting scopes, which were disappointing, I bought an Orion Short Tube 80 (general purpose scope, not waterproof). Much sharper than comparably priced units sold as dedicated spotting scopes. Also have a Meade ETX-90mm, which is nice for some uses, but tend to use the lower magnification (and wider field of view) Orion more. Standard 1.25" eyepieces can be swapped between the two scopes. Have an older Bushnell 20x I use at the 100 yd public range.