I have a BPS Upland Special (22" VR barrel w/Invector chokes,
http://www.browning.com/products/catalog/firearms/detail.asp?value=011B&cat_id=012&type_id=216 ) that is about perfect for everything as is, IMHO. I don't know how much extra barrels cost for BPSs or how widely available they are- I have the idea they are scarce and expensive compared to more widely sold shotguns. Only thing is, for trap you'd REALLY appreciate at least a 28" barrel to help with the swing... I don't shoot trap 8^).
Someone mentioned the BPS High Capacity- I don't know if they make longer barrels for those, as the barrel ring seems as if it would be in a different place.
I don't know Novas at all. Never ran across a deal on one, and they don't appeal to me enough to pay retail to get. I'm a cheapskate, I'll settle for a good old model Remington Express for $150-175 far too readily to chase more expensive stuff, except to experiment with. I like a couple of other pumpguns that show up cheap from time to time also, notably the Stevens 520/620 and the High Standard Flite King/J.C. Higgins Model 20.
Far as I know the new Winchester pumps aren't in wide distribution yet, so no one really knows anything about them yet- at least I haven't seen any hands-on reviews so far. I have one on order at my favorite FFL dealer's place, at that price I couldn't resist. If it's a 1300 clone, that will be great. Dealer says they are made in the USA, that's a good sign far as I'm concerned.
Best bet IMHO is something with widely available, relatively inexpensive spare barrels. That lends the advantage to Remington and Mossberg, as best I can figure it.
fwiw,
lpl