There are some very good tropical fish sites on the internet highway. Personally I have one prefered site that I spend most of my fish related leisure time on...but there are about another 6 or so that I like to visit as the craik and banter on the message boards are slightly different. I say go for it...put all of your effort and resources into it coz if it don't work out, then at least you won't be thinking what might have been for the rest of your life!!
I have no real idea of the logistics and issues of starting a board....but I wish you all the luck in the world if you decide to go for it.