Trust me they are never going to find a true replacement for MS Dhoni. They might find someone who is a good captain but as I have been saying for a long time, MS Dhoni was the best captain for India and CSK. I actually think that he was the best captain ever in cricket. To me, there will be a debate between MS Dhoni and Mashrafe bin Mortaza because these two achieved unbelievable things with very limited resources.
Anyway, I also think that CSK should look for a player to potentially replace Dhoni. Otherwise, they are going to face a lot of problems in the upcoming years.
Dhoni was no doubt one of greatest captain India ever had. Under his captaincy India was able to win T20 and ODI world cup along with ICC champions trophy. No Indian captain has this honour. The best thing about MS is that he left international cricket at the right time and with honur, this is something not common specially in players of subcontinent. Since CSK has won IPL under his captaincy its very much clear that MS is fit for next IPL also. MS always gae surprises, lets see he has some surprise for his fans next year or not.