It's a tough call. 700c definitley gives you the whole market, but I'm not totally sure you'll find it easy to put your feet down when you stop or start tipping over. I actually run a 650b up front but the tyre is pretty chunky so the outside diameter isn't that different to a 700c narrower tyre anyway. I'm 5'11" and it's comfortable for me so I'm trying to interpolate what happens for you.
I rather like the Rene Herse tyre I have up front, it's been surprisingly resilient to visitations (punctures) despite its lightness and thinness. And if you're going that route then you probably need to order off the internet anyway; they're not as common as Schwalbe. Is the answer therefore to order a stock of 2 or 3 inner tubes and tyres so you don't need the niche products from a local bike shop?
