Stanley and husky have a extending handle 3/8 that has a fairly small head.
It's the #1 ratchet. I don't think Husky even sells that ratchet still, but I have seen it in WalMarts.
http://www.trucktrend.com/news/1210tr-truckin-tough-3-8-inch-ratchet-test/
I do own a Snap-On frankenstein long...