Their track wheels include clincher and "sew-up" (meaning tubular) rims. You don't want tubulars as they're not practical for street riding. I'm not familiar with all the combos listed, but I run a CXP22 on a formula
hub and have had no problems.

The flip flop hub that is fixed/free has a thread on for a BMX/SS hub. It allows you to run either fixed or SS on the same wheel (and allows the manufacturer to make one hub for both markets).

Practically speaking with normal use (i.e. not loaded touring), you're probably fine with a 32 if you wanted, but I tend to prefer 36 spoke wheels with 3 cross lacing as the most practical wheel.


edit: As regards to the individual shop costs, you'd need to call. Some shops are smaller too, and there may be a wait time if you want a custom build. Some shops have finished wheels on hand for people like you who are looking for a hand-built wheel set.