I have the SIOchef bags in two sizes and LOVE THEM - started with two and bought two more for bigger items after six months. They don't seal, but then, they don't have to - they're tall enough to fold over the top of the pot, and as you lower the food into the water they're easy to squeeze the air out of because they're thin and flexible; they'll also keep releasing air for that reason, if any's trapped in the food, so food's less likely to be a float risk. Vacuuming is a bit overhyped in sous vide (itself a misnomer) - what matters is not having enough air to insulate any part of the food from being cooked thoroughly. They include a pair of soft silicone zip ties (removable) for securing the bags to the handle of the pot or whatever you prefer.
I've been using mine for a year and change, and they've been durable and easy to clean, just invert over your hand and sponge off with some soap - they've been pasteurized by the cooking process. If you have to dry several, pop them inside-out over something tall (e.g. wine bottle). I've heard concerns about lingering odor or flavor - if I cook something REALLY INTENSE (uh, curry) and plan to do something delicate in the bag next (egg pasteurization) I sometimes pour a little vinegar in that bag and cook it alongside next time I cook another one with food in it, as a deodorizer, but I doubt that's especially necessary.
At first I thought they were so soft they'd be flimsy, but I haven't managed to damage any of them yet and I'm a bit of a lazy klutz in the kitchen (and have long fingernails).
Good on you for cutting your plastic use!