You may go through this in kind of a back door manner...
Use this dealer locator to find a dealer in your area then ask them who uses the materials in your area, they may be able to steer you towards a few contractors they regularly supply with the material....
Dealer Locator - Schluter-Systems
Another possibillity is to pick up the John Bridge Book...
The Kerdi Shower Book - Mold-free, Leakproof and Accessible Tile Showers
Read up and try to DIY it....
You have the second bathroom so it's not like you are under the gun to have it completed in a couple of days...
John Bridge has an excellent tile forum second to none, to help you and as far as the plumbing portion I'll be here.
I would encourage you to think about upgrading the shower mixer as well while you have it torn out...
Delta came out with an excellent valve a few years ago, the R-10000 universal valve. Basicall it is a universal valve that is used on tubs, or showers. It comes with many trim options and can be ether thermostatic or, pressure balanced and have just temperature control or temperature and volume control. One valve fits all and you pick what you want it to do... You can also change it to a different type at a later date if you change your mind.
I have seen many posts by DIYers that have done Kerdi showers them selves in the manner I have described with excellent results.