On a two-class domestic flight, eVIPs book into A inventory, as do miles+copay upgrades. Upgrades are by elite class and time of request. Whether eVIPs or miles+copay have precedence is the subject of a long-running debate on FT, but I suspect irrelevant to your situation, as there aren't likely to be a lot of non-elites requesting upgrades on your flight.

It was indicated upthread that there was no inventory of miles+copay upgrades. The disadvantage of trading for an eVIP is that the person you get it from has to apply it to your PNR. If it doesn't clear, they still owe you an upgrade, so they have to do it again. If someone trades one to you now, it will likely expire on Feb. 28, 2011 unless used before then. Getting it to clear on a worthwhile route before then as a non-elite will be tough. I would recommend sticking with miles+copay if you want to upgrade that badly.