Re-charging trucks A/C system?

 
  Can anyone recommend a good A/C recharging kit product maybe available at O'riely's autozone etc.. The A/C in my Dodge is only blowing slightly cooled air now (Only a few degrees above ambient). Truck is 2002 Dodge 2500. I know there are recharge kits available, but I would like some info the better kit.

I have had good luck with the harbor freight guage setup.