I'm trying to find a really heavy duty, jumbo size vacuum storage bag (or two). I need to store the extra bedding stuff I have for guests, and I don't have a lot of room. Specifically, I need to shrink one of those foam mattress toppers and a duvet (so the bags need to be big).

The ones I previously bought from Zellers are PacMate Vacusac and they vacu-suck. The valves leak and none of them have ever sealed properly. So, I'm on the hunt for some more. Any suggestions? I don't know why somebody hasn't made these out of good vinyl yet...