Besides budget and required runtime, what's the environment? You'll need different lights for urban riding with streetlights than you will on pitch black country roads.

I've got a Metro 550 which I think might suffice for both situations (I'm hoping anyway) though I'm a little concerned about runtime. Up to now I've had nothing but generic two part (light and batteries separate) and they work great, I got the Metro for summertime flashing use just for the convenience of having one piece, but I'm going to see how it does in the winter with 50 minutes each way and see if it'll run full power for a whole day without recharging.