As bradtx said, there are still a lot of square taper cranks for sale, many being mtb cranks:

http://aebike.com/parts-accessories-...nsearch=Search

This one is very popular for touring although a little pricey:

http://aebike.com/product/sugino-xd6...r1030-qc30.htm

You should go ahead and "cold-set" (bend or spread) the dropouts so the 130mm hub will fit easier. Then have your RD realigned. You'll need your rear wheel built and true for your LBS to perform the alignment, since it relies upon the rim as a point of reference.

I'm not sure a Schwinn Sprint will make a decent tourer. I suspect this frame has short chainstays, which means you'll need small feet or small panniers (or both) to avoid heel-strike when pedaling.

You may also want to reconsider building up an old, perhaps poorly-suited frame for another reason - building with all new parts is expensive. You can sometimes buy an entire bicycle on sale for nearly the same cost. Your attached parts list with $90 added for a BB and cheap crank, plus another $25 for spokes and $30 for S&H totals $667. This leaves out the necessary seat post, saddle, 2 brakesets, stem, handlebar, brake levers, bar tape, bottle cages, which I assume you're recycling from the Schwinn Sprint.

Here's a few cheap touring bikes that that come to mind:

http://www.nashbar.com/bikes/Product...202339_202326_

http://www.bikesdirect.com/products/...an_turismo.htm

These are practically the same bikes - they have identical frame sizing. The NB has 105 brifters, while the BD has DA barcons, better gear ratio for touring, a better crankset and better wheels.