I am looking for a wheel upgrade in the next year or so. I ride around 2000 miles per year on mainly county roads and highway shoulders usually over rolling terrain. I am looking for a bombproof all purpose wheel set that is at an appropriate price point for my bike. At this point I ride at around 16 - 18 mph. I'll probably put Continental 4000s tires on the bike.

Should I:

1. Buy a factory built wheelset? If so, which one?

2. Get a custom wheel built? If so, which rim, which hub, other decisions?

3. What spoke count?