HD Live Capture (aka Capture Now fcp7) into FCPX

I imagine that if you can capture live footage from an onboard iSight camera, you should be able to plug something a little nicer in that gives you a little more control. I've been struggling with this for the past few weeks and have been to a few different stores to test cameras and haven't found anything that works yet.

My criteria for the camera needs to be HD and I need to be able to get a lav mic plugged into it.

Other than that, I'm pretty open to whatever (preferrably something around $2-5k).
Any thoughts and input would be greatly appreciated.


Thanks,
Ian