I've built several different styles of sawhorses. I found that no matter
what style or size I chose, I was constantly battling the balance between
stability, size and storage space. When you go for foldup or collapsable
styles, you begin giving up stability, in my experience.

Recently, Home depot and Lowe's started carrying a collapsable steel
sawhorse that is absolutely marvelous in how little space it takes, yet is
very stable. I decided I could not do better than a pair of these. They
cost about $19/each, have adjustable height, and measure 2" x 6" x 38" when
folded up. You can bolt a wood work surface to the top.

Bob