Me again... Another option is to use Futura as body text. I’ve explored the fascinating typophile thread on the subject, but I’m not convinced its a good idea.

Don't use Futura for much text.

Try this: http://www.myfonts.com/fonts/emigre/mr-eaves-xl-sans-opentype/

hhp

Although it's an obvious choice - a geometric sans serif, like Futura, but humanized by some oldstyle features - I would definitely say that you should not use Kabel.

A sans-serif face that might be used in a dictionary, with a large x-height - I don't know any by name. Antique Olive certainly has a very large x-height, but it is usually thought of as a display face. In a thread here on a related topic, Century Gothic was recommended, but for your specific case, it seems to resemble Futura too closely.

I suspect you should go for something wide, not narrow, and lighter rather than bolder, so Bell Gothic is out, even though it's legible in small sizes, and has the additional useful property of clearly distinguishing between I, l, and 1.