I know ezquake does, but are there other quakeworld clients that support this?

FTE. Maybe one of those modified FuhQuake clients, but i'm not 100% sure. Darkplaces support them too.

I actually tried use FTE the other day.

I downloaded the Full GL-only version from

http://sourceforge.net/project/showfiles.php?group_id=116842

It seems to use the pcx skins by default.

Seems to be totally different than ezquake.