I'd call a 12V starter in a 24V system an 'emergency capability' at best. I ran that way after I bought a new starter from CarQuest. Despite assurances that it would work, it was never ideal. It spun much faster than it should have, which was great some of the time, but more than half the time it seemed to fail to engage the flex plate teeth. Later when replacing the flex plate, I found some teeth broken off and other places where they'd been chewed up.
OD Iron has the 24V starters, you can find them on eBay, and NAPA has them, but not in the computer, I think it's in the 'Heavy Equipment' paper catalog or somesuch.
If you don't want to spend the $$$ for a new 24V one, converting to 12V starting is realtively easy and reversible later. As a bonus, you can actually jump start your CUCV! This comes in handy when you leave your lights on... all night... ten miles from a paved road... don't ask