Co2 regulators+needle valves

Alright...

 I've been using DIY CO2 for the past five years and I'm about ready to
purchase a REAL CO2 system. I probably could be putting a down payment on an
Acura NSX with all the money that I wasted on sugar and yeast.
Never-the-less.
I remember looking at regulators at a brewery site. I was getting slightly
confused at the selection...too many choices. Needle valves... are they realy
needed? 
Can someone give me a link to their co2 system notes. Or perhaps recommend a
certain size regulator, brand or model # etc.

Thankyou

Neight