The Surley bikes are good, and it's a nice company to support. But, they really are not light! They are quite heavy actually. For a good steel frame.. maybe a Lemond Poprad? Not sure if they still make that one. I assume custom is out of the question? You could do a steel frame, coming down from top-of-the-line material and still get something good quality and light from some framebuilders for not too much (that's always relative, isn't it). One of my favorite framebuilders for a low-cost steel frame that is really nice is Curtlo:

http://www.curtlo.com/

Take a look there an see if that might be a good option.

RC