swap type site help

my first post and just to let you know i am not a webmaster. at the moment i only use wordpress to create sites.
i am trying to create a swap/barter type site and i was just wondering if anyone had any info on what wordpress theme and plugins would be suitable for this.
thanks in advance
thanks for reply.
ya i was thinking about that but i wasn't sure would a classifieds or forum type work better.
any suggestions for a good classifieds theme?
also i noticed on other sites that users can be awarded points for participation. is there a plugin available to do this automatically?
i know you're going to say go search for these myself but i have spent a lot of money before on so called premium themes and plugins that were not really suitable for what i needed and i am just hoping that someone on here might have had previous experience with what i am looking for.
as far as I know SiteMile is one person, but I've had good experience with them in the past. Development can be slow on some products, but they are solid, and you can chat directly with the developer.