Most GC's that I deal with are interested in one thing; the price.
My proposal/bid consists of an outline of the work, as interperted from the prints/specs, a list of fixtures, mfg & model, and the wiring methods that are being used. Sometimes, we list the number of switches/recept/etc. We also list switchgear, panels, etc., and attach cuts.
I use an excel spreadsheet for the numbers, and sometimes include that with the proposal/bid.
Lately, we have been doing a lot of design/build and T&M work, which is a good thing; less paperwork.
If I can help you any further, e-mail me