Water mixing station

I am looking to build a mixing station and I think I have a design down that I like as far as plumbing but I have no idea what type or how strong of pump I need. My RO/DI unit and barrels are downstairs from my tank and I am trying not to break the bank on a simple pump. If anyone knows how strong of a pump I would need please let me know or if you are selling a pump that would work let me know, thanks everyone