As far as the Nova goes, I've never had one, but before you buy one I'd advise you to verify how much a slug barrel costs. When I bought my super black eagle, I inquired about a slug barrel and all I remember is it was very expensive.
I ditto the other people's comments about Remington 870's. I have 2 wingmasters(12 and 20 gauge) that I love. I used the 12 as my primary shotgun for 25 years and with very heavy use it has never failed me.
The Ithica model 37 is a well loved clasic too, but I had a bad experience with an old one I had. Plus good luck finding a slug barrel for the Ithica.
IaCraig