The advice I was always given (as a non-psych major) is that it is far more important to get research experience than to take more classes. Obviously, the more classes you're able to take, the better, but just thought I'd throw that out there in case they start to become a significant drain on your time/funds or you find yourself having to choose between another couple classes and a job as an RA.
Surprisingly, I was also told that I didn't need to take the psych GRE (and so I didn't). I agree it sounds like a good thing to do though-- just, again, if you find yourself having to choose between studying for the psych GRE (which could take a LONG TIME it seems to me), and getting more research experience/studying harder for the general GRE, you might want to consider opting for the latter.
If all these things sound counter-intuitive just know that it worked for me! Everyone's situation is different though. Feel free to PM me if you want to discuss in more detail.
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