For sturdy, adjustable and cheap go to your local home center, such as Home Depot. Get what it called a roller stand. They are adjustable in height and very sturdy. They are made to support wood beyond the base of a table saw or a planer. It will have a 2' diameter by 10' roller on top If you go to the plumping department you can get some pipe insulation to cushion the roller. The nicer ones have one leg that folds into the other to make it compact for storage. They cost between $20 and $40 US dollars.
There is a picture of one here:
http://simplest-shop.com/tools.php/Mode/related/
AsinSearch/B0000223R1...
I have seen these used by the local CAP unit for there Blanik L-23. It worked out well.