wrote:
Which ones are most likely to be heard? What would be a reasonable
antenna for longwave? I've never heard anything but beacons on LW, but
I do like the hunt for them.

There are some web sites dedicated to hunting and identifying
Non-Directional Beacons (NDBs). This is one I like:

http://mare.radio.tripod.com/4ute.html

Also look in to

http://www.lwca.org/

Most NDBs are pretty dull listening. A very few broadcast AWOS and ASOS
weather from the airports where they're located. But that's about it.
I'd be more excited about transatlantic LW reception...

DE AB3A