I'll gladly shill for KoolStop all day long. They turned my Dia-Compe center pulls (from Rivendell) from death-traps for the unwary into pretty good brakes, even with non-aero levers. Good pads really make that big a difference.

As for the reach issues going from 27" to 700c, the difference in brake pad placement is 4mm. If you can lower your current pads 4mm or more, you can switch over to 700c with no issues.