Question:
Can anyone know where to find commercial reverse osmosis? I need heavy duty (metal housing) with unit without filter(s) change if possible? Something like any water goes in (include salt water) and come out 7ph with better then 98% effeciency on removing salt, chlorine, chloramine, heavy metal, etc. Of couse, I am not sure all above description is possible and with below $ 2,000?

Answer: Well, as far as I know filters are a good thing and almost certainly an inescapable requirement for any RO unit. Our lab uses a sand filter and/or cartridge filter in front of even mains tap water.

I am not sure, however, of what you mean by "commercial": I have seen large-scale membranes and they look just like my home-unit (a Kent Marine Barebones - extremely basic 10 gpd unit), only bigger. In desalination plants the membranes are mounted in various appropriate configurations (so many in parallel, so many in series) inside concrete tubes or similar. The tubes are stacked on metal frames.

In my opinion, you need to have a better idea (better than what you wrote) of what it is you require. Points you should take into account are

Water usually comes out acidic (pH less than 7) in the commercial plants. Post-treatment is normally used to give it an adequate pH. Mine, however, appears to be high (pH=8) but that changes very, very easily...