I've been happy with 46:19 on similar terrain. These are just the gears that I happened to pull out of my bin one day. It seems to be the sweet spot for me. I'm not super athletic, so I can work as hard as I want and not spin out except on long descents. I find myself riding a bit faster than on my geared bikes, just to get into a comfortable cadence, so it helps keep me from getting lazy.
In a sense, single speed means getting used to always being in the wrong gear.
