Good spoke wrench, $5
Butted spokes at $1 each (more or less), $36
Rim Strip, $5
Sun CR18 $40 (this is a touring bike, right?)
Hub - your choice, up to about $60
Sheldon Brown guide to wheel building, or perhaps your library has Jobst's book

Or, http://www.rei.com/product/770555/de...00c-rear-wheel from REI for $80, and pay your local shop to retension it.

If you're going from 27" wheels to 700c, you will need to check that the brake pads will reach the rim; diameter is different.