New solar set up

Just bought a used caravan and I'm going to scrap my old van and move my solar to my new van. At the moment my solar is setup parallel 12volt. Two by 200 watt panels with a 30amp controller plus another another set up the same using a separate 30amp controller plus one 300 watt panel with a separate 30 amp controller giving me three separate controllers feeding two 160 amp 12 volt lithium batteries. In the new caravan I only have room for one controller and I'll be using either four by by 200 watt panels or four by 300 watt panels on the one controller. My question is what size solar controller should I buy if I use either panels -price concern between the 800 and 1200 controller .