Just use your current bike. No need for a new bike to tour with since racks and/or trailers can be hooked to your current mountain bike. From the picture of the 820 mountain bike on Trek's website it looks like there are mounts for a rear rack on the seatstays. Mounting a front rack on the suspension fork would require the Old Man Mountain rack sold by Adventure Cycling. Or get a rigid steel front fork for $65 from QBP at your local shop and use any front rack.
Cheap panniers can be found many places. I use Nashbar panniers. They have worked for me for about 6,000 miles of loaded touring.
Based on these suggestions it would cost about $40 rear rack, $40 front rack, $65 rigid fork, $100 panniers. That is total for both front and rear panniers. Or about $290 for the BOB Yak trailer and bag. And $25 for skinnier smooth tires to replace the knobby mountain bike tires. Then go ride.
And if you hate your current bike for touring after doing it, then you can move the racks and panniers or trailer to the new touring bike you get. You have to buy the racks/panniers or trailer no matter which bike you tour with. The money is not wasted.
This message was edited by RussellSeaton on 2-23-05 @ 3:49 PM