Right now, I have a pair of Tropic Stars with the interchangeable lenses. They fit nicely, but I wouldnt mind something with a little bigger frame or larger lenses. I have tried on a limited number of Costas due to no one around me dealing them.

The specs on the Tropic Stars are: Lens size: 55, bridge 19, temple 120, 8 base

The only problem is that I am apparently sunglass spec illiterate as I have no clue what those numbers mean.

I will be looking at the copper 580 lenses.

Can you guys recommend any of the styles you think might fit my face?

I think your melon is easily as big as mine, so look for a  L/XL frame.  ManOWar is a good place to start.  Fathom and Hammerhead both feature L/XL frames.

http://www.costadelmar.com/store/Departments/Sunglasses/Expedition.aspx

Costa Del Mar - Swordfish model # sw11 with the blue 480 lenses.