First you need to check MD regulations concerning legally hunting with a hand gun. Many states require specific bullet diameters and specific energy levels at certain distances.
IE.......... Colorado requires a barrel length of at least 4 inches, a bullet diameter of .24" and have a minimum energy level of 550 foot pounds at 50 yards to hunt all big game except mountain lion which requires 400 foot pounds and a 45 grain bullet.
So the .357 magnum (all but the heaviest loads from Buffalo bore and Corbon) would be illegal for everything except for mountain lion in Colorado.
Having saind all that
................ I would reccomend a .44 mag to start and should I ever take up hand gun hunting I would most likely purchase something chambered in the 454 Cassul or possibly the .460 S&W or the 500 S&W.
As far as the gun itself goes it would be a revolver obviously. It would have at least a 7" barrel and as long as 10 inches. Brand name really doesn't matter all that much. Most all make exceptional revolvers. Ruger, S&W, Taurus, etc...