I also have a 4 x 4 table router. My current setup uses two shopvac heads. This seems to work OK, although more vacuum is always better. If I plate off the open portions of the spoilboard it will hold a 6 x 18" piece of flat material as long as I don't push it too hard. Basically it comes down to making sure you block the small pieces in to help keep them from sliding. A vane pump would be nice, but I need to stay. within the hobby budget.