The one you link to is the correct VDI cable; there's only one model/style and it works with all VDI-equipped devices.

The JTV guitars do not come with a VDI cable; they come with a similar cable designed for the Workbench hardware interface which also comes with the JTV guitar. It does look exactly like an regular RJ45 on one end; the other end (connected to the JTV) is shielded/protected like a VDI cable.

You can build your own with any length of pre-assembled CAT5 network cable with RJ45 ends and these: http://www.neutrik.com/en/data/ethercon/ethercon-cable-connector-carrier/ne8mc to protect the ends.

The one that Line6 makes is of good quality, though, and is black and more plyable.

I've done a little research, figuring I'd build a custom cable. I've had a lot of success building 1/4" mono cables for guitar and pedal board, and have saved a bit of money while assuring a quality cable using neutrik plugs and the like. www.redco.com is an excellent source for all cable parts and they are great, except that their shipping charges are high on small orders ($11 or so.)

I've come to the conclusion that the $30 cable with free shipping from places like Music 123 and Musicians Friend is a very good price. The 25' cable consists of about $20 in parts:

Pair of NE8MC is about $5

Rj45's are about 50c

Duracat cat5e cable is about 50c per foot - this might be a higher quality cable than the Line6 cable - or it may be the very stuff they use.

I was gonna cover it with some techflex at 17c per foot.

With the shipping I was always right around $30 per cable.

Other manufacturers (Whirlwind) are extremely expensive by comparison.

Kudos to Line6 for creating an quality affordable product.