i need a temp / humidity controller

i am about to set up a grow tent and am going to need to control my temp/humidity so they work together and with co2 too.

i ran across this and wonder if anyone can give me some feedback on maybe a cheaper method or whatever. any info or help would be great



http://www.nehydro.net/index.php?main_page=product_info&products_id=394&zenid=8b29a39299cbe920b5df5d6d5c681863

also found this one on ebay - i wish there was a cheaper way to control all these things

SENTINEL EVC-1 ENVIRONMENTAL CONTROLLER FREE SHIPPING - eBay (item 130253129356 end time Sep-16-08 14:30:39 PDT)

this one looks really nice too. any feedback will be appreciated

CAP AIR-3 Temp Humidity Climate Controller Hydroponics - eBay (item 330217489166 end time Oct-01-08 22:58:25 PDT)

Most people love their CAP stuff.

I went the hard way and did a DIY (humidity still to come) But its more tweakable.

thanks. i really didn't want to spend $200 bucks on a controller but it looks like i am gonna have to