greg,
It really depends on what batteries and regulators you are using. It is excelent that you plan to use 18g wire and deans. If using a single Li pack use a 4 cell series paraell and a good regulator. Check your voltage under load after each and every flight. The rule of thumb is no more than 4 high torque digitals per regulator. It also depends on the type of flying you do.

1 4 cell 4800mha series paraell lithium cylindrical pack is 6.2 oz, 1 regulator is 1.5 oz, 1 switche 1 oz. total 8.7 oz
2 2 cell 2400mha series lithium cylindrical packs 6.2 oz , 2 regulators 3oz, 2 switches 2 oz total 11.2 oz

weight savings 2.5oz...peace of mind..pricless