Hunters_life made some pretty good points.

I'll add that you should probably start with a good 50x209 inline. You probably can't go wrong with anything from one of the major manufacturers like T/C, CVA, and Traditions. Find the one that fits you and your preferences.

Also, don't necessarily go for one just because it has the "magnum 150 grain charge" capacity. Unless you're after really big game or are going to shoot at longer ranges, I don't think 150 grains of powder is necessary.