co2 questions, +rep for help

I,m an advanced newbie. I'm flowering my first 5 plants that range from 4.5' to 6'.

Anyway, I'm getting ready to set up a new veg room and I want to add CO2 which I've never used and know little about. In order to start getting things set up I need to know a couple of things...........

1. I know CO2 comes in tanks, but I had heard something about a "CO2 Generator" that makes CO2 so you don't have to keep getting tanks refilled. Do these CO2 Generator's really exist and if yes, what are they called?

2. I read in a paperclipped thread that there are CO2 detectors that can turn the CO2 on & off in order to keep the CO2 at a certain level. Same 2 questions, does it exist and what's it called.

+rep for any and all help

yeh it burns like gas fuel they exist and aint cheap. pointless just get the regulator for like 150 bucks
Sentinel CO2 Injection Regulator Kit (.5-15 CFH)

This is what im about to order for my room. http://www.bghydro.com/BGH/itemdesc.asp?ic=ACO2CGEN1NG

this is a propane powered generator.
HydroGen Water Cooled CO2 MiniGen Generator, LP
but like i said above. get a 20 pound tank and the hose and regulator... voila! youll have dinosaur sized plants in weeks!
mine look like Jurrasic plants they LOVE IT!