I am using LifePO4 !
I have 8 CALB 3.2v in series for a 25.6v bank. I have four 300w 36v panels that keep them very happy using a Morningstar TS-60 MPPT
One thing about LifePO4 is that they are most happy at 28.0v. Make sure that the controller is able to custom the setting. The Battery Monitor System is very important. Here is the basic outline of my BMS system and what is going on for me to live completely off-grid !
[caption id="" align="alignnone" width="830"] Alan’s LifePO4 BMS and Charging[/caption]