If you are thinking about the Encore I love mine. As far as stock and barrel I like the stainless barrel and synthetic stock for the muzzle loader. The stock is durable and the stainless is satin. Stainless is a lot easier to take care of and as far as glare off of the barrel I look at it this way, if he sees it it is already too late. Go smoke him!! As far as the 700s go they are great guns, I own 6 and have no complaints. But in the long run Encore with diff. barrels will be cheaper on the pocket and you will still be just as happy with the performance. Take your time fall season is still sometime away.
I know this isn't one of the three from which you are choosing. But, if you are looking for small, flat and fast, allow me to recommend the Ruger 6.5 x 55. (.264). It is an excellent gun for what you are looking for. And as far as reachin' out there, I took one this year from 170 - 180 yds. Dropped him like a rock.