Different phases of the project may favor different working heights, adjusted for your stature and comfort. I decided to spring for a pair of height adjustable sawhorses made by Stanley, and so far am glad to have spent the little bit extra on them. IIRC they run about $60/pair from either Lowes or HD, and maybe others. They adjust from 30" to 37". Ref post no. 534 on the following page...
http://www.vansairforce.com/communit...=29232&page=54
The only down side is that they have to be unloaded and folded flat to change the height, but so far that has not been a problem for me.