Hey Jb1. Karyn is absolutely right. The video function in Sonar is just for playback, and it makes more sense to edit your audio first. You can get away with a whole lot more fudging of video shots and angles than audio takes! There are lots of consumer digital cameras that will give you great results. I have a couple of Canon handycams that have served me well. Get creative and throw in a couple of GoPro's as well! Most consumer models use very compressed formats, such as avchd. Most editing suites now support these formats, but due largely to the compression they are processor hungry and do not support smart rendering, so production is a bit slower than the pro formats. This doesn't stop you from getting great results of course. If you are recording live gigs, one of the specs you should look at when choosing a camera is its low light recording performance as conditions will often be less than ideal. Check the price, the specs, then watch some amateur video demos on YouTube - they will give you a much better idea than any manufacturers promo.
Video editing is great fun - and a nice break from audio. If you are familiar with a DAW, video editing software is not a huge leap, and there are many very capable editors for under $100: Sony Movie Studio, Corel Video Studio, Cyberlink power director etc. My goto editor for many years has been Sony Vegas, but it is a bit more expensive (and recently discontinued!).
If you get the chance, record in the same venue over a couple of gigs. Then your 2 cameras turn into 4. If you do record the gig on a single night, I suggest one camera be raised up on a tripod and the other be hand held and mobile. That way you always have a stable shoot to return to when editing, but have the variety and creativity of the mobile camera.
Good luck and have fun:)