Personally, I prefer square frames, so that when a number of different images are on the same wall, horizontal, square and vertically orientated images don't result in a variety of "footprints" on that wall.

These frames are store-bought - frame, glass, mat and backing all together for $40.00 each (the prints are 11x14).

Apologies for the blurry digipic with reflection. If it was better, you would be able to tell that the frames are black, and the mats are a slightly warm white.