There are literally dozens of options that you can look into. What Ga are you wanting? Most people use a 12Ga, but I have seen 20Ga do pretty good for skeet too.
The main thing about skeet, is it's not like trap. Trap it is more benificial to use a full choke, improved and modified chokes are nice too just not as effective as a full choke.
Skeet is the exact opposite. You are going to want an open choke, and in some places, open chokes are sometimes the only options allowed for skeet.
That was for the Barrel, Now lets get into the different types of shotguns used. Typically, I've seen pumps, O/U's, and Semi's used for both trap and skeet. Pump's are the second most common, but you have to be "on the ball" to get your 2nd shot off. The most common and becoming the most popular is the Semiautomatic. You can get your 2nd shot off almost instantly after your 1st shot. Your timing will still have to be right so you dont unload both shots in the same spot. (some semiauto's have touchy/hair triggers). The best shooters that I have ever seen, use O/U shotguns for both trap and skeet with interchangable chokes. They use O/U's so they have one shot for each skeet target.
As far as brands, Berreta is okay, I personally dont care for them... but the choice is really for you to make. Other options you may take interest in is Browning Citori(spelling?), Ruger Red Label, Mossberg Revelation, or a Franchi for O/U shotguns. Semiautos: Browning, Benelli, Verrona(spelling?) is a new one, Remington and Winchester may have a few. For a pump: Mossberg 500, Remington 870, Savage 30 series, Benelli, Browning(maybe, they haven't really done alot of pumps recently),...there are honestly so many you would have to google them or wikipedia to find them all.