You could go with a "wide" compact crank, 46-30 up front. Sugino makes one and it is expensive as you pointed out. If you buy it direct from Japan, you'll save some coin.

There are some square taper ones that would do the job from IRD and velo orange (both 46-30). They probably look too retro though for your set up.

The shiftmate 8, if it works, looks to be your best bet. Micro shift makes 10 speed MTB compatible bar end shifters.

Frankly, I don't think a compact crank is your best bet for touring and it might be worth your while to bite the bullet and get the sugino double to get the gearing you need.