I recently started skeet shooting and love the sport.  I currently have a Citori Upland Special 24" that I use to quail hunt.  The gun is great for that, but limited at skeet shooting with it's 24" barrel.  I'm looking to buy a new O/U with a 28".  Would you go longer than 28"?  I'm looking to spend around 2K any suggestions?  I've noticed a great deal of the upper end sporting clay guns have ported barrels, should I go this route?

There isn't much gained in having a barrel longer than 28 inches, unless you shoot trap, with the only advantage being a longer sight radius for those 20+yd line shots or playing the games where your shooting at birds from the back of the parking lot.  

In 12ga O/Us, most are balanced with  28inch barrels.  The best velocities with almost all commercial loads and most target loads is achieved with 28 inch barrels.  And it provides a decent site radius for 99% of all types of shotgun shooting.  

Balance allows the gun to swing smoother.  Site radius allows for better shooting, sort of like how one can shoot better open sited rifles better than handguns, because the sites are further apart.  Top velocity is nearly allways checked against 28inch barrels with the exception of slugs.  

I think there is merit in porting in regards to felt recoil.  

Another topic of discussion is lengthening the forcing cones a little.  Will help with your patterns by easing the shot into the barrel vs ramming it all into the barrel in 5/8 to 7/8 of an inch.  Many top custom guns have their forcing cones lengthend by an inch or so.  

24" barrels will do just fine for skeet shooting. Just put skeet chokes in it and you should have no problem busting clays. I use a 26" skeet barrel myself.

The trend in Sporting Clays is very long barrels, 30", 32" or longer, with chokes that extend the barrel length even more. Porting will lessen barrel rise to get you on the second shot quicker on doubles, as well as lessen felt recoil. I've seen some stands where I need all the help I can get to get to break a pair of particularly difficult doubles.

I agree on having the forcing cone lengthened. That is probably one the best mods you can do and it doesn't cost that much to have done. Some shotties come that way from the factory.

I don't shoot a lot of skeet, but it does seem to me that those dedicated to shooting skeet and skeet only do use shorter (24-26 inch) barreled shotguns with open or skeet chokes, seems to help for those fast cross shots.  

For what its worth, I don't think you can go wrong with another Citori, they have several models for trap, sporting clays, wide ribs, raised ribs, ported, etc etc etc.  They don't typically have lengthened forcing cones, but I had mine done for $60 a barrel or $110 for both a couple of years ago.  Nice improvement in pattern shape and density.  You could definetly get away with a very nice Citori skeet gun for less than 2K, with porting, lengthened forcing cones, adjustable stock and trigger.  

I have both 28" and 30" shotguns. I feel the 28" is about optimum for skeet. 30" is OK for skeet but really more suited for trap / sporting clays.

My main gun these days is a Beretta AL390 gas autoloader with 28" barrels that I use for most everything.

Some of my shotguns are ported and some not. I can't tell any difference between them. There is a big difference in recoil though between shooting an O/U and a gas autoloader all day long. The gas guns definately cut down on recoil and after a couple hundred rounds it starts to get to you.

You mean an 18 1/2 inch Mooseberg 500 with a Surefire light and a TacStar side shell holder is NOT the perfect clay busting weapon?

Sure it is Joe... for "tactical" skeet.

Haha, I have a mossberg 500a, w/side shell holder, pistol grip, heat shield w/18 1/2 inch barrel. I took it skeet shooting and didn't do to bad except for the fact that I was the laughing stock of the skeet range that day!!

I use a Rem 870 with 22 inch barrel. I love the way it shoots but I too have been approached by locals at the range that proceed to pick on the gun till they see me shoot. Looks funny as hell with the side saddle and two round mag extension