Here is the mms.apk I'm using. I think it's actually from Beta 1 or Beta 2 of this ROM, as this is the primary 4.2 ROM I've been using. Here's some info about the apk.
- It needs to be copied to system/app and its permissions set and then a reboot
- It is not inverted
- It does split
- It does have working mms
- It can be themed with cm10 themes that work that way
As far as other themes go, I didn't notice any major problems using it with this MMS.apk, but they did seem to act a little funny with some of the themeing/settings already in the ROM. Granted I didn't really dig too far into that and it could have just been my notification drawer settings were set weird when I applied the theme or something. Also, everyone likes disclaimers around here. If you use this apk and it breaks your phone then you probably did something wrong, so always make a backup!
Edit....definitely ignore my signature! I never sign into the web site