Upload & Sell: Off
What would be the best option for a 24mm e-fov lens with these, do we think? I probably wouldn't buy a leica or zm lens, but I have a canon 24 L right now, so I could have some flexibility to sell/trade. I'm actually wondering if a 10-22 efs wouldn't be a good option.
If AF is OK, and f/4 is fast enough, I would try the Sony 10-18 OSS. I think it's a pretty good deal, though I haven't owned one myself. Most reports show that it's pretty good optically, and the OSS is handy even for such a wide lens if you're taking pictures in twilight. If Zeiss hadn't announced their 12mm about a year ago I'm pretty sure I would've gotten the Sony.
Otherwise, for 24mm exactly, your options are limited. Either an SLR lens + speedbooster as sebboh mentioned, or the Sony 16mm which is so-so (though, also tiny and relatively fast at f/2.8).