'm looking at the VSD X or Defi BF Tachometer as my main tach. Either of them are going to be attached Defi-Link CU II with exhaust temp, oil pressure, and oil temp Defi BF gauges.
Basically, which one do I want and why do I want it?

VSD X http://www.nippon-seiki.co.jp/defish.../vsdx_top.html
BF Tach http://www.nippon-seiki.co.jp/defish.../bfta_top.html

 

using links that work might help

 

Yeah... that site had one of those "web page within a web page"... that's why the link didn't work.
Here is the target site:
VSD X http://www.defi-shop.com/product/vsdx/vsdx_top.html
BF Tach http://www.defi-shop.com/product/bfta/bfta_top.html

 

I'm a real gadget geek... so I would prefer the VSD X.
You mentioned that either way, you were going to attach one of these to the Defi-Link, but the BF Tach section has (in red lettering) "BF Tachometer cannot be linked to the Defi-Link System."

 

I didnt look too closely at the sites, so I might have missed this. But from the pictures, both go up to 9000 rpm. The HUD does 9.5k maybe. You might want to consider this since you can rev past 9k... I usually shift at 9300 or so.