So all of your actors will be wearing a mic in front of their mouth? I guess that would work if your film is about operators in a call center...
You're not going to get decent, reliable wireless sets for less than $600 each; that's a fact of audio life. Yes, you can definitely get cheaper stuff, but you will have to deal with drop outs, RF interference, added noise and other fun artifacts.
I just don't like the Zoom H4n; its build is flimsy, it eats batteries like crazy and the mic preamps are very brittle sounding. The build of the Tascam DR-100 is much more solid, Tascam has experience with production sound gear and the preamps are much smoother. Oade Brothers even offers a mod for $125.
The R-24 is for musicians; it would be very hard to put in a bag and operate it while doing run and gun. And if you're willing to spend $500 spend another $80 and get the Marantz PMD-661 - smooth mic pres, good interfacing, etc. Get a fully modded unit from Oade for $680.
Com'on MDM, you know what I'm going to say even before you ask the questions!