If he isn't Red John, then he is most certainly involved as when Jane showed the video of the 7 suspects to Lisbon, she said to Van Pelt something along the lines of "Jane's paranoid that Red John has read his mind because he knows the 7 people who Janes thinking of". The only way Red John would've known the 7 people that Jane thought it was is if he saw the plan that either Jane created in his apartment OR the one that Kirkland copied when he got two guys to break into Jane's apartment to take photos of the plan, which he then recreated in his office. That is the only way that Red John could have known Jane's 7 suspects because Jane didn't tell anyone about them- not even Lisbon- until he got the video from Red John.

Also, Kirkland from the start has this high-pitched and soft voice which Red John has. I noticed this similar voice in episode 2 of season 6 when Red John phones Jane and has Lisbon, painting the face on her.

I still don't see Kirkland's motive if he is Red John, but he's been interested in the Red John case from the start and had a copy of Jane's plan which makes me think he is either Red John or is working with him...