Ditto @reddeercity
I also have a 5DM2 and absolutely love using it with ML! I also have the T4i and was able to get 720p @ 24fps continuous raw video and found the nightlies to be very stable overall (of course a gremlin sneaks by once in a while, as with any nightly, but they are corrected very quickly). There is also an alpha build for the T4i and that's pretty solid, but I don't know if it has all the 'latest'.
As far as being a 'work in progress', I'm not familiar with the T5i development cycle, but some builds are more considered 'rolling release' type these days, so don't expect a 'milestone' date where a 'stable' release will be delivered, that's how I understand it anyhow

Also let me say, if it's a choice between the T5i and T4i and you can save some dinero with the 4's, go for it, because the cameras are literally the same, see here:
http://snapsort.com/compare/Canon-Rebel-T4i-vs-Canon-Rebel-T5iNow I see you mentioned 2 cameras, if that's absolutely necessary, then consider the cost of the 5DM2 (5DM3 will be out of your $ range), because with your budget you may only be able to afford one

P.S. Although you will find ML support for all compatible cameras, the 5DM2 support is absolutely fantastic here!