Python Air Mass Sensors/Injectors

[KWeiner64@aol.com]

I recently noticed an advertisement in European Car from NOPI Custom and
Performance.  It lists both high performance Python Air Mass Sensors/Air Flow
Meters for the S4 and V8 which come with a "rheostat set p" that allows
engine performance enhancement adjustments from inside the car with the turn
of a "knob" (it says if you leave the "knob" in the normal position the car
will remain emission legal) -they are about $250.  NOPI also lists Python
higher flow fuel Injectors for the S4 and for the V8 for about $60 .  Does
anyone have the following information:

1.  Is Python a reputable/knowledgeable/reliable maker of these products and
in turn is NOPI a reputable/knowledgable/reliable distributor of high perf.
products? 
2.  What will each do respectively to the performance of these cars? (I am
particularly interested in what effect they will currently have on my 18psig
boosted, RS2 manifolding, and K & N coned 94 S4).
3.  How much do they each effect fuel economy?
4.  Are they street legal?
5.  Has anyone out there tried this or similar perf. upgrades - and what has
been your experience?

TIA for any advice/info. you can provide
Marc Weiner   EMail: KWeiner@aol.com
94 S4 & 90 CQ  
R.I.P. 88 80Q & 91 200 TQ