I also like the Bushnell Dusk To Dawn. I have the standard eye relief model on my Encore M/L and the long eye relief model on my Encore slug barrel and on my .45-70. I like the extra eye relief on these big kickers so I don't worry about cutting my brow. At 100-150 yards, I am hard pressed to say my Leupold is a better scope but it sure did cost a lot more. I also have a Simmons and it is a very nice scope but I think for the money, you can't beat the Bushnell line-up. If you watch the adds, Bass Pro has some good sales on them during hunting season or pick one up off of eBay.

As far as power, the 3x9x40 does everything you need. Just remember to keep it on the lowest power setting to start with.