The Vortex scopes are very nice. In their line, I prefer the Viper series over the Diamondbacks. Another solid choice would be Sightron Big Sky scopes. Very nice also. Regarding the ones you mentioned, I'd put the Buckmasters last but, it in itself, is very doable. The Monarchs are good too. If it were my choice now, I'd jump on a Sightron Big Sky. Many have rebates also. Good luck.