My Remi 1100 Sporting 12 came with four extended chokes. This is just another reason I liked the Sporting 12 that comes only with a 28" barrel - an extra inch for an odd total length of 29". I think it's just a great length for any clays sport.
Couple-O-observations I've made about 'em:
1) Not a big deal, but beware of that extra inch when it comes to your shotgun carry cases. I use a break-down soft case made by Boyt. They come in three different sizes - small (28"), medium (30") and large (34"). I tried the small case, but no-go with that extended choke (unless I removed it).
2) I find that I need to periodically reach down and tighten my extended choke, sometimes two or three times during a match. I only tighten it as much as possible by hand, and never use any sort of pliers. As it's an external choke, there are no groves to use a wrench on it either. One thing I've been meaning to buy at the grocery store that will likely resolve this issue is one of those rubber jar opener pads - I think the extra grip it'll provide will be just right.