I don’t use my vacuum sealer for fresh chicken meat, mainly for vegetables. If you cut the chickens into serving pieces then the 11” should work, especially if you get the roll and cut it to the length you want. I have not tried to get a whole carcass in an 11” bag but I could see where that might be a challenge.
I have a Foodsaver brand that can handle an 11” bag but I just buy the 8” rolls and use those. I just cut them to length. For what I freeze the 11” bags were a waste. It’s amazing how long food stays fresh in the freezer with no ice crystals or freezer burn.
One of the problems you have with these is that they suck moisture out of the bag when they pull the vacuum. If the bag is wet where it is supposed to seal, it will not seal. Practically everything I seal has enough moisture in it that you cannot seal it. The way I get around that is to fill the bag and freeze it overnight, then seal it the next day. I only work with two or three bags at a time so it doesn’t thaw enough to release moisture during the vacuum process. Mine has a moist button and a dry button. I don’t know what difference they make. When I push the moist button it still sucks enough moisture out that the bag won’t seal. To me that is not a great feature.
You can get attachments to some to seal canning jars or other things. I don’t bother. The only features I use is to seal on the vacuum setting and to seal without a vacuum. There are a few other buttons on there but they are never pushed. There is an attachment in the vacuum chamber that catches any liquid that is sucked out of the produce. Since that is removable that makes it easier to clean.
I cut my chicken into serving pieces and double wrap that in freezer paper using freezer tape. I find if I single wrap it bones can poke a hole in it. Double wrapping gets around that. I save parts of the carcass for broth and put that in zip loc type bags. There are two problems with that. A zip loc does not keep it fresh that long, ice crystals will form, freezer burn if you leave it a long time. Vacuum sealing will take care of that. But those bones have sharp ends. It’s really easy for those bones to poke a hole in that zip loc bag, not so much when you first freeze it but later when you toss things around searching for something in the freezer. I don’t think the vacuum bags would be as bad as zip loc’s about that, but it might be something to watch out for.