Todd, the Encore is a great platform for a M/L.
Here is a link to a post describing my load and showing range results. http://forum.hunting.net/asppg/tm.asp?m=788990
Here is a link to another post showing results with a TC Omega. http://forum.hunting.net/asppg/tm.asp?m=785673

I would definately go with a .50 caliber M/L. You will have more flexibility with pellets and bullet selection. My best suggestion, if you don't have a lot of time for finding a load, is to use 2 pellets(pyrodex or 777) and a powerbelt bullet. The pellets and powerbelts are both easy to load. After this year's season, start playing with different loads to find out what your rifle likes the best.

Good Luck!!