Scott, developing an online web app to do this is fairly simple. Just have to deal with increased hosting costs do to adding server technology, ability to identify unique users, and ROI. How would make enough money to warrant the work?
Eric, my thoughts exactly. I'm thinking it should be drilled down by fish species, shipping/delivery region, state, then services provided. A lot of this info would have to be entered and guesstimated by the end buyers, so there could be potential issues with keeping that data accurate.
Could it be kept so simple that it can be accomplished similar to a topic in the archives. No added cost, but time for someone to update it. An average user could not edit it to mess up data or add trivial comments. This then would minimize wrong info put in by any random person.
Side thought--
The problem that I see with just a list, supplied over a long period of time by forum members, is that some will no longer exist and be dead ends to the consumer. If there was just a very small annual fee to be included, that might help keep the list fresher. I belong to a magazine (and advertise in) that once a year lists all suppliers free of charge. It is up to each advertiser to send in their current info ( or just say repeat my add) by a deadline each year to be included for the next time. This is just one way to keep it a fresh list.
-- I am just throwing out ideas, not meant to sound meddling. As always, easier said than done.