Cheap Shotgun/Boom Mic.
 

What would be the best money to quality mic that I could get? Ill be doing a lot of vocals, mostly two person stuff. I already have two lavelier mics (Countryman) so would it be smarter just to buy wireless transmitters for those?

A good shotgun mic that is only $150 is the Røde VideoMic. It has a built-in shock mount as well as tripod, boompole, and camera mount points. It uses a 9 volt battery and conects to your video camera with a 1/8" stereo jack. This is not a stereo mic, the signal is just split to fill both channels. Røde also has a Stereo VideoMic for $250.

Musical vocals or "vocals" as in recording dialog and interviews? As for wireless - useful but there's an old adage that says "whenever you are able, always use a cable." Wireless is a fall-back strategy for those situations where a boom or wired lav isn't practical.