Another option is to go with something like a 26" choke tubed barrel. Good for most stuff. You can add to it later as funds allow.
Sights for the rib are pretty cheap.
Or you can get a removeable scope mount for the receiver, B-square I think they're called. ( I'm not sure).
A lot of the mossbergs have tapped receivers too.
Lots of, or should I say too many,lol, options.
You can sure drive yourself nuts with trying to decide, been there.
Maybe hit Shooters choice in Waterloo and kick some tires.
ATB
Oops, I guess we were typing at the same time...