I have a similar set-up. Currently 12 x 12V 170Ah batteries, increasing next week to 16. I use Victron BMV. See: http://www.victronenergy.com/battery-monitors/BMV-700
Works very well and gives me all info I need on battery bank: Sate of charge, current in or out, etc
My inverter is a devel lpt 6kw I have 18 x 300w 48v solar panels 2 x 60A mppt and all 4 battery strings are on a bussbar so I am thinking of getting a victron bmv 700, I don't need the 702 because the midpoint is not going to be used because of the common buss, what do you guys think