Depends on your finances. If I had little to no money, this is what I'd do:

i. trawl Craigslist and find a cheap (but quality) early 1990's mtb with good condition drivechain. Budget: $100 (at least in my area, they do come up)
ii. keep all the original drivechain. Put 2 slick tyres on. Budget: $80 (let's say you go with Schwalbe Marathons and new inner tubes)
iii. buy some cheap bar ends (budget: $10) or put trekking bars on (budget: $30 for bars, $30 for stem, $10 for bar wrap).
iv. put front and rear racks on (budget: $60)
v. fenders (budget: $20)
vi. front and rear panniers (budget: $60)
vii. front shelf rack ($10)
vii. front handlebar bag ($50)

Even then, that would make a touring bike that would be reasonable for $390 -$450 including racks and panniers (I included front as well as rear as let's assume the wheelset will only have 32 spokes and it might be a good idea to spread the load more) and depending on some options. You may even be able to get it lower depending on the cost of the bike, not having fenders, etc. If I didn't have that much to spend, I'd just p-clamp a rack to your current bike and just go, though given the gearing and wheelset, I'd probably want to be touring very light.

if you have more of a budget of $800-$1000, personally I'd shy away from the Nashbar frame and building it up UNLESS you currently have spare components AND the tools and mechanical know how to do it yourself. Really the Windsor/Fuji/LHT full built bikes just make more sense from a financial point of view. If I had a $1,000 budget, I'd be tempted to get the prebuilt LHT, though if it really was only $1,000 I'd go for the Windsor/Fuji and buy the racks and panniers to go with it (as a prebuilt LHT won't include panniers, front rack and handlebar bag -and they are certainly an expense)

Good luck!