Rode makes a couple variations on their videomic. It's designed to mount on the hot shoe (it doesn't use any of the electrical connections in the hot shoe -- they just use that as a way to mount the mic.) They're extremely good mics.
If you're doing bands/concerts then I'm wondering how far you are from the performers -- are these small venus, bars & clubs... or are these concert halls and you might not be very close (and keep in mind that if you don't know anyone in the band, a lot of venues won't let you bring in a "professional camera" (which they often deem to mean any camera with a "removable lens") unless you have a photo pass.
In any case... my favorite concert lenses tend to be my EF 135mm f/2L and the EF 70-200mm f/2.8L IS. Usually the most challenging part about concert photography is that the light isn't bright enough for a kit lens... that f/3.5-5.6 variable focal ratio -- which is f/5.6 when you're zoomed in -- isn't collecting a whole lot of light. An f/2.8 lens is collecting four times as much light and an f/2 lens is collecting EIGHT times as much light.
Switch the camera to "spot" metering mode and test the exposure against the skin/face of a performer. Don't let the camera use it's default "evaluative" metering or it'll generally over-expose. BTW... it consistently over-exposes by between 1 & 2 stops. That means if you do want to use a semi-automatic mode, you could also just set the exposure compensation to decrease by 1 to 2 stops.
The Canon 430EX II speedlite is a great flash. I own that as well as the 580EX II. The 580 has a built-in bounce card / catch-light card (although a white 3x5 card and a rubber band can give you the same thing for a 430). If you eventually end up owning multiple flashes and want to do multi lights, the 430 can only be a "slave" in a multi-light setup. The 580 can be either a slave or a master. Apart from that, the differences between the 430 and 580 (other than the guide number... the 580 is a slightly more powerful flash) are fairly obscure.
I have not seen a 600EX RT (I'm sure it's great -- I just haven't had one to try myself.)
I like the size of the 430. Most of the time, the 430 is all I need so it's nice to have the slightly smaller & lighter flash.