I bought this drive

http://www.microcenter.com/single_product_...duct_id=0345763

I put it into the M$ hdd enclosure. Will my Jtag read it and format it or do I need to do something for it to show up?

It'll be read just fine. A retail or stock console won't read it, but any exploited console will.

Thanks for the help! Will I need to format it or will the Jtag take care of that for me?

You can format it in the dashboard.

What's the limit on the size of drive we can use in a jtag?

I would imagine 2TB.