Just because you want to use 700c wheels doesn't mean you need to reset the dropout spacing to 130mm. You need to check the spacing on the hub of whatever wheel you plan to use. If you've got a steel frame, fitting a 120mm spaced wheel on a 130mm spaced frame or vice versa isn't usually much of an issue.

The BB spindle size is dependent on what crankset you use, and the cup size is dependent on your frame.