I've had two LifeBlue 125 ah batteries for almost 3 years now. I have a Xantrex 2000 watt inverter connected to all the outlets in the TC and have 460 watts of solar on the roof.
I went with the LIfeBlue batteries as they have a built in bluetooth system that provides all kinds of battery info, takes the place of wiring in a system for the same info.
You have to get as much solar on the roof as possible, maybe just buy the one battery now and fill your roof with solar and if you need more then buy another battery.
Do however make sure you purchase a good MPPT controller, I us a Renogy, and get it large enough to handle maximum solar panels you will have on the roof.
Cheers,
Eric