You know, gamespy and planettribes could help you. After all, they already host the download for tribes rpg. Why not give them a buzz and ask for a lift.
Do you know somebody who owns a business?
You know, I just thought of a brilliant plan. My grandfather owns a firm in downtown memphis. What i am thinking is that I could have his firm host your forums. I believe he has business class DSL, and Im sure there isnt that much traffic going through it.
But I will need details. I need to know what you would require, if hosting this would be transparent (leaving no icons, etc.) and if there is anything else I need to know.
What Im thinking is that I could just sneak it onto their server. They have only one IT guy, and he only drops in when they have computer problems.