Bulk reef supply has excellent systems and can even have a 1:1 ratio. I done suggest anything of eBay as you get zero support or warranty or refill cartridges.
Returned your PM...here's the thread. Pic is on post #24. It has new filters and membrane is less than a year old (good for 3-5 years). The ONLY thing you need is new DI resin soon. You'll still get "0" right now though.