The last bike I assembled for a friend is the Hot Karl. It was a SRAM shifter and it just isn't very good. Shifting problems keep re-happening and the foot hits the guard. The former is exactly the kind of pain-in-the-ass I don't want to deal with. The latter is a basic design flaw that can't be fixed.
I bought the bullet and ordered yet another Shimano Nexus hub. Strange that Sheldon Brown's place seems to have a lock on their sales. I tried to buy one online through Ebay, but the place that was selling the older (heavier) model doesn't have any in stock. Anyway, when the hub comes I think I'll just take it to my bike man and pay him to swap the hubs/build the new wheel. I don't really want to bother. But I do feel I owe my friend a good bike.
[November 10th Update: the Hot Karl is back in business and she's never been hotter.]