The two sizes of the Cross Top levers are listed by the size of clamping portion of the handlebar, this does not reflect the actual size of the clamp on the brake lever.  All road (drop) bars taper from the canter portion of the bar to a smaller diameter, this narrower section of the bar is the intended position for the lever.  Therefore the lever can be purchased based on the clamp size of your bars and should fit the bar on the narrower section.

The reach is adjustable from 47 to 57mm.

Yes, the SCR-5 levers create enough cable pull for linear pull brakes.  The SCR-5 is not compatible with V-brakes or mechanical disc brakes.  Note:  Avid’s BB5 Road Disc brake is compatible with the SCR-5 lever.

Drop V levers are not compatible with standard road or cantilever brakes. They must be used with linear pull brakes such as V-brakes. They are also compatible with mechanical disk brakes.

All Cane Creek brakes use Shimano-style brake pads.