FI tuning

[jab86@cornell.edu]

i am very used to the older, pseudo mechanical FI systems from rabbits, 
and loved how i easy they were to tune for performance.  all i needed was 
an allen key and a voltmeter.  i had certain O2 sensor voltages that 
corresponded with power, fuel efficiency, etc.  what is a good way to 
performance-tune the system i have on my 1990 80 quattro (cis-e, 
i think)?  

also, does anyone have/know where to get an air/fuel mixture 
gague?  i have heard of really snazzy led ones that allow you to 
constantly be in the know.  any idea where to get one?  anybody selling 
one?  thanks a lot.

-joe
1990 80q - 138k mi