Some models of the Foodsavers have a "marinate" button that allows you to pump air out of bag with meat and marinade, but then stop it at the right moment to seal it.
This is the one I got. It's expensive, but WELL worth the extra dough. I use these Foodsaver Zipper bags because I'm constantly prepping meals for the freezer, and these bags make work VERY quick and clean.
The biggest benefit of the sous vide, to me, is being able to put frozen pouches in of prepared meals, and to that end, these tools are worth their cost.