In my opinion RJ is either Brett Partridge or Sheriff Thomas Maccalister.About sheriff i dont have any clues but he seems really suspicious to me.

About Partridge lets take the things from the beggining.1)Bruno Heller said that we can trust the list.
2)He also said that we will be dissapointed when we found out who red john really is.3)He also said that the first episode of the mentalist s01e01 is very important to the RJ story.In this episode we have a fake RJ murder BUT Partridge appears on this episode.And think about it the man we try to find for 5 seasons is on the first episode.Thats the importance that Bruno Heller mentions in the episode at my opinion.4)Partridge characteristics are like those that Rosalind Harker gave to PJ.5)At s02e08 his right red hand we see red john kills Janet Peak.In this frozen image of this episode we clearly  see that the man with the hood is Partridge http://thementalist.wikia.com/wiki/Janet_Peak?file=Vlcsnap-2012-10-09-23h24m43s165.png .6)In last episode of s5 when the other guy says that he wants to work with a serial killer we clearly see Partridge saying Hi! 7)He is also at the right age according to the Red Barn episode(s05e13).

Now about Bob Kirkland.He obviously isnt RJ.First of all Lorelei said to PJ that he shook hands with RJ.When PJ shook hands with BK Lorelei was in jail....So the theory about BK being RJ isnt true.Although i believe that BK is one of RJ friends inside the FBI and thats why he stole the informations from PJ's Office and also killed the other RJ servant(that was clearly an order from RJ himself).

About the last episode RJ is not a psychic.The whole show is about mind games and NOT supernatural powers.I believe that he took this memory from PJ just after the time PJ's wife and daughter killed by him.If you remember PJ was in clinic for a year.I believe at this time RJ achieved to take this memory from PJ without PJ remember that he told someone about it.