MultispeciesTamer,
While you may have a sincere desire to give some good advice here, your lack of knowledge /experience pertaining to Cichla should have overriden that desire.
Cichla Kelberi DO grow past the 16" mark and are known to hit 24" If not more. On the same note, these are probably the most difficult cichla for a beginner and not worth advising to spend $100+ on a fish they will inadvertently kill. Many of us here whom have kept Cichla for YEARS find Kelberi to be very stubborn fish...especially when it comes to adapting to food other than live. If you've kept Cichla, you would know not only how different in behavior they are to LMB, but how much they eat.
I dont even suggest getting cichla off of live until atleast 6".
As for tank size, a 150 g tank, even a 75 g is a good TEMPORARY home. Kelberi grow very slowly compared to the other species of cichla and may stay in these tanks longer than most, but these are not suitable life-long homes.
Ryand63,
Cichla Orinocensis, Monoculous, and ocellaris are usually readily available in the hobby. I suggest obtaining a couple and giving them a shot for a few months. If it goes well, and you will want to continue with cichla, you will want to upgrade in tank size.
-Laz