The XT version is the hybrid with the SSD and traditional together. The non XT version is the standard drive. All XTs are 7200. The price is average, and I have one and like it, although some have had issues so be warned. The latest firmware is obtainable through Seagate's website with the instructions to flash to it. It is super easy and menu driven.
Yes it is a Momentus XT. You can get them online for that price on newegg, amazon, etc. Is that drive used? I wouldn't buy it if it's used. Get a new one.
You'd be overpaying by $2.
$99:
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148591
http://www.amazon.com/Seagate-Momentus-7200RPM-Hybrid-ST95005620AS-Bare/dp/B003NSBF32
And you know those are the Hybrids, and they're new.
Not an app. Burns the image to a disk, restart and follow the menu prompts.
Yep, restart the computer and hold down the 'C' button. That will go to a screen which asks you which startup volume you'd like (otherwise it always just automatically goes to your default startup disk) and follow the prompts.