Touring - Building up a 520 frame What should I avoid

I just picked up a 17 in Trek 520 frame circa 1992 hopefully a real steal at $36 + shipping. I plan on building it up as an excersise in learning more about bike mechanics. I am looking to you all for some expert advise on what components are best suited. I really do not plan on any unsuported touring but want a rig other than my Dale or Mountain bike to pull a trailer on the MUPs or ride an MS 150 type of event. Of course any free or cheap parts from your garage bins would be most welcome.

If you're not going unsupported, then you won't need to worry about very low gearing or bomb-proof wheels. It sounds like you're trying to go cheap so barcons or DT shifters will save you significant money. So will an 8 speed drivetrain over a 9 speed. I don't know what the rear spacing was on the 520 in '92 so you want to check that before you decide on hubs. Any decent 32 or 36 spoke double-walled eyeletted rim should be fine.

How fast of a rider are you ? Your average speed helps in figuring gear sizes. Gear sizes help determine types of shifters and derails you can use. Then the rest can be whatever you can grab.
Then for fun ask what kind of saddle is the best ;)

Truthfully, I am pretty darn fat and slow, but I imagine I will gear it either the same or a touch lower than the triple on my Dale. As far as asking about the best seat I already know that most people here are all for the Brooks B-17. I just want this to be a fun project because if I don't like it as much as the Dale, then I will sell it. Right now I am focusing on whether to get a carbon fork or go with a good chromolly fork since the frame is without a fork. Thanks for the input.