Originally Posted by Andy_K

Yeah, you need to match the spindle length to the crankset you're using. Each crankset will have a particular length bottom brack spindle it's designed to work with.

Since you're building wheels, I would strongly urge you to go with at least 8-speed components. You may not need the extra gear, but it will prevent compatibility problems down the road. A 7-speed freehub is only compatible with 7-speed cassettes. An 8-speed freehub is compatible with 8-, 9- and 10-speed cassettes. It will make the wheelset more versatile. It also gets you into much better quality components. You've selected a really nice set of rims, but a fairly cheap hub. I'd suggest upgrading the hubs and downgrading the rims. I think Tiagra hubs are the best value on the market right now. For rims, something like Mavic CXP22 or Velocity Dyad would be a good choice, arguably even better than Open Pros for your purposes. I notice you don't have spokes or nipples listed.

I'd also go with a higher grade rear derailleur. At the level you're looking at, quality goes up much faster than price. If you want a wide cassette like you've got spec'd right now, you'll need a MTB rear derailleur. The Tourney RD is junk. You can get a Deore LX RD for under $40. IMO, it's well worth the price difference. Front derailleur is a bit less critical, so the one you've got is probably OK. The only caveat there is that the curve of a front derailleur is generally designed around a particular chainring size, so with a 46-36-26 crankset, you may want to look for a MTB front derailleur. That would be a problem if you were using indexed front shifting, but since you aren't it doesn't matter.

I think you've got the wrong brakes planned. With the C'Mute frame I believe you'll want either V-brakes or cantilevers. Your brake lever options are limited if you go with V-brakes, but you'll have a much better braking experience. V-brakes with Travel Agents aren't a bad option if you have a particular brake lever in mind that has short pull.