Well, firstly Mac341, there are no National Guard unit with slots for PsyOp soldiers right out of AIT afaik. If you want to be a 37F you'll have to go active duty or join the Reserves. I know for sure there is a Reserve PsyOp unit in San Diego and they are on active jump status. Your recruiter should be able to let you know every unit in your area you can go to with the MOS you want to enlist in.
Weater you realize it or not the National Guard will limit a lot of MOSes from your choices. Which is why if you are elligable to join the military you HAVE to check out Active Duty and Reserves, otherwise it is just plain ignorant.