Well, I've turned the heels and picked up the stitches on the barter sock. It turns out that the band heel has worked like a charm. I haven't tried on the socks yet to see how well they fit, but all of the stitch counts are correct and there are no gusset stitches to decrease out! I had to modify it a bit, as I started the heel on a purl row instead of a knit row. I did this because I wanted the center of the back of the heel to align to the cast-on point, and I find it's easier to start a heel flap on a purl row when you do this. This also meant that I got to use k2tog / ssp instead of SSK / p2tog, which I think is more symmetrical.
The band heel uses a Dutch heel, except slightly narrower than the traditional one. I'm wondering if there is a way to work a modified square heel instead of the Dutch and still come out with the correct number of stitches. I imagine it shouldn't be too difficult, but does involve sitting down and performing some math. I don't think I'd want to go with a rounder heel than a modified square heel, since the heel flap is pure stockinette and would probably be too baggy otherwise. Well, now that I know the rules, I can break them on the next sock! By the way, if you're not familiar with the various types of heels you can knit, check out the Knitting Geek's sampler and this should clear things up for you.
Knitting from both ends of the same skein has proved a lot easier than I first imagined. For some reason there is actually less twisting involved instead of more, probably because the ball is in a central location and is very easy to untwist. This method does have the disadvantage, however, of putting you in a pickle if you don't put your yarn ends in the correct spot each time. After I turned the heel, the one sock yarn was wrapped around in the center several times, and while there was probably a way to untangle it with successive rows, I just found it easier to slip the sock onto 2 dpns temporarily to take the tangle out. If you use 2 separate balls, you may get this problem but can fix it by unwinding the problem ball through the center, between the socks. That simply doesn't work with 1 ball, because you will tangle up the other sock if you try that.
Onto the foot!