Why not a merlin and a di vessel?
Do you know if you are in a hard or soft water area?
Have you good water pressure?
I have a DI vessel, a 11 litre from Daqua filled with resin already so was going to just get the Pure Freedom RO. I also have a CLX27 and a backpack, but been waiting on this RO to be let down

My TDS is 195
Not sure on pressure but will get a booster pump whatever.