sounds like a plan... I did something similar with one of my mountain bikes. The SS conversions with the spacers make it easy to get the chainline correct, and you've already got a selection of cogs to choose from. One thing you didn't mention that you'll need to get are some single speed chainring bolts (unless you've got a bashguard or are going to leave the big ring too)

One of the coolest things I noticed about riding SS is that it improves your overall bike fitness; you get stronger from mashing and also get to practice spinning. When you get back on your tourer you may find yourself riding it differently than before