Shot this group at 200 yards off a bipod with a 2.5-8 Leupold LER scope on an XP-100 that I had just put together. Killed a black bear with it a week later at 277 yards. Was down a dark hillside and I had no problem finding him in the scope, and picking my spot on his shoulder. -Could have shot him a lot farther if that had been the case. The best advice I can give you would be to practice as much as you can with what ever scope you should choose out to the max range that you expect to shoot. There's no substitute for good shot placement. With time, you will find that locating your target in a pistol scope will become more natural. There is a learning curve to it just like everything else.
I have a Bushnell 3200 2-6 w/firefly reticle that is really nice in dark timber, or at those last few minutes of shooting light. It sits on top of my TC Contender 7 TCU Super 14 barrel.
I don't own one of the Weaver scopes, but I have heard good reviews of them.
The Leupold does have brighter, better contrast glass than the Bushnell or Burris scopes. The eye relief remains fairly constant too throughout the power range. -I still really like my 3200's and Burris scopes...
Obviously, the LER scopes don't have the light gathering ability nor the field of view of a rifle scope, but without putting a brake on your 6.5 CM your options are somewhat limited.