Cody - Take the time to look around. I know that diamondback and panther(Classic) both offer a booklet with prices for all the various options listed in it. American used to do it, call and speak to the ladies in the front. Tell them you are THINKING OF BUYING A NEW RIG and would like some type of price list from them. I bet they will send you something. Call Alumitech, I still like those guys, nothing fancy but solid as hell. Call Mark's as well.
Between the 4 of them, you could get an estimate of what you want would cost. Of course all the bells and whistles will cost more. But do this before you visit any of the places. Then visit "Airboat Trader" on line. I have seen some nice rigs on there that would be excellent starter boats.
For bow fishin, I would assume that a larger hull would provide a more stable platform. Especially if you were not going to run dry.
Remember - If they talk like a snake oil sellsman, they just might be one.