So I've shot a few weddings now to build up my portfolio, and I'm continuously running into the problem of not being able to focus accurately with the 60D's screen, especially in bright sunlight. No surprise there, it was only a matter of time before I got fed up with it. I've also played with MagicLantern's focus peaking, and I just don't like it that much.
If I pick up a small field monitor for this thing, will the focus peaking be built into the monitor itself or is that always a function of the camera?
Depends on the monitor you purchase. Some have it as a function, some don't. All of the SmallHD ones have it as a feature of the monitor, independent of the camera.
I run several SmallHD monitors (DP-4, DP6, AC-7) here and I really like those monitors in terms of cost vs quality vs features. Warren Eig on here just reviewed the SWIT S-1070F and he really likes it. ( http://forums.creativecow.net/readpost/325/1889 ). I believe he actually bought one as a result.
You can also check our Marshall and Ikan for other options.