I'd get the 870,but be warned that the express model will rust in a heartbeat. Its especially bothersome when hunting around saltwater. Most days I hunt saltwater my 870 already has rust forming before I get home.

Its not that big a deal to take care of it though,a silicone cloth removes most of it with a bit of rubbing.

I have a Nova I bought new and while its a good workhorse I always go back to my 870,the 870 just fits me better and that means I shoot it better.