There's no reason you can't go with 700c wheels if that's what you prefer, especially since you don't have cantilever posts to worry about. If you go with center pulls, there are plenty of long reach options, both vintage and modern, that would have enough reach. For vintage, look at Weinmann Vainquer 999 or Mafac Raid. Even Mafac Racers, which are much more common and inexpensive might have enough reach. For modern, the Paul Racer is a beautiful caliper with plenty of reach, but is pretty expensive.