There's Red Sector, that's been around since the original B5 game. Not been updated in a few years, but the URL is http://www.redsector.net/
Shame; the guy had an few ideas for a ST:Voyager but in B5, dumping the pc's ship beyond the Rim, but that was from before he built his newer site.
Someone did a complete gaming source for the B5 station, plans and all, but I can't remember where it was. Few years back again so Its probably down.