I know it has a XLR input, but how about the regular mini-jack mic input?

No mini-jack input, no.

the avx100B does have a mini jack output though so you can monitor your audio while recording right?

Yes, it has a headphone output jack.

Thanks.

I also noticed that there are 2 versions... A and B. Whats the difference?

The "A" has been discontinued, replaced by the "B". The B stands for Better, if you ask me. Lots of very nice improvements and refinements throughout. On the Panasonic webpage, or on the dvxuser review, you can find details as to what's been changed from the "A" to the "B", but -- simply put, unless you have an overwhelming need for time-lapse recording, the "B" is the superior camera.