$1000 is kind of an odd place for O/U shotguns. It's generally above Turkish import level and below the Browning/Beretta level.
I've owned a couple of CZs and while they are good guns, all mine have been a bit oversprung. Hard to cock on open and heavier triggers. I find that kind of annoying in a hunting gun so they got sold. Not all of them are this way, so I recommend getting one in-hand before you buy it.
The Browning's and Berettas are great guns and I highly recommend you save a bit more money if that's what you want. A few years back I was set on buying a Franchi SL for my desert quail hunting addiction, which is their light weight alloy framed gun. Great 6# 12 gauge gun in the $1,400 range. I did some serious introspection and recognized that I am just not all that nice to my guns. So I ended up buying a light-weight Yildiz for $430. It's become my go-to bird gun for about 4 years now. Weighs a tenth of a pound more than the Franchi and fits me well, uber reliable, and a thousand dollars less for those times when it falls off your bumper in the rocks or you slide down a rocky slope chasing Mearns. One of my hunting partners has a Beretta Silver pigeon. Great gun too. Like $2200? Doesn't fit me at all. Point is get some guns in your hand and see what works for you.
Aside from the guns mentioned here. The Weatherby Orion is a good one. It's one of the better Turkish import guns. The Winchester 101 field grade that is sold through Cabela's and Bass Pro is another good one roughly in your price range. Have another buddy that has the latter. Really nice gun for the money. They were supposed to be a lower grade wood than the standard 101s, but his looks really nice. It's about 3/4# heavier than my ugly Yildiz (about the same as a Citori Lightning or a Silver Pigeon), but shoots about the same as mine.
If you find something like a Citori or a Berretta you really like that's more than your budget, by all means save some more $$. If you've ever left a gun sitting on your bumper while taking care of an injured bird dog, and then drove off with the gun still on your bumper, spent an hour and a half looking for it, and found it in the bottom of a cattle guard a mile and a half away, consider a Yildiz or a Tristar.
