RE: Sheeting Foam wings
You don't have to use a vacumn bag.... I use a press(full wing length) I built years ago to squeeze the skins on under a 6" piece of laminated MDF using 1/4" allthread running through my workbench. Very cumbersome and heavy but it does an good job keeping everything straight and places quite a lot of pressure on the skins. You can even use a good board and stack a lot of weight on top (this is how it was done for years by almost everyone). Books, bricks, blocks approximating the weight of a small car(just kidding) would be about right!
That said... the vacumn bag system is by far the best, but if you are on a budget, there are alternatives that will provide acceptable results.