ITC Avant Garde Gothic Alternate has some cap height lowercase alternates such as a, e and m. (Click on Stylistic Alternates to view.)

Font Bureau's ITC Franklin has unicase alternates:
http://www.fontbureau.com/fonts/ITCFranklin

You might try searching for "unicase" too.

Thank you so much! This is really helpful. :)

For your search, I also think some people are calling the 'biforms'?

Cheers!

there is an old thread around here somewhere with almost the same title. i remember someone had mentioned Disturbance. the quite like the regular weight.

http://new.myfonts.com/fonts/fontfont/ff-disturbance/

I think the "e" in the logo is nothing but a "G" flipped vertically and then with the bar extended. All the other letters are capitals.

Michel

For your search, I also think some people are calling the ’biforms’?

And still others use the term "unicase." [EDIT] D'oh! Altaira already mentioned it.

One well-known typeface in this category is Bradbury Thompson's Alphabet 26, but there are others.

http://typophile.com/node/18746

unic (Unicase) is even an opentype feature tag and you can select it in Hypatia Sans Pro: if you write "lettering delights" in smallcaps except fot the "e" for which you choose "unicase" as Letter Case, you get