larry - Do not get the buble type with a beam in the end, their
worthless IMO.

I was in the same boat as you. I got a black and decker self leveling
rotary laser for pretty cheap. Its the cheapest one I could find and
works great. Its not 360deg though which is fine for what your doing.
See
http://www.consumerreports.org/main/...lder_id=356263
and
http://www.amazon.com/exec/obidos/tg...48027?v=glance