I have the Gast PA-50 from Stoney Creek. It is fairly quiet and I placed it under an Artificial Boulder. I am fairly happy with the system. I would suggest the weighted tubing if you can afford it. I got the non weighted and placed 2ft sections of 1/4" rebar every 8 feet or so and it did work, it was just a pain dragging everything in place. Also when you put it together make sure you place pipe dope on ALL the galvanized fittings. I didn't at first and after 1 day of running it was leaking like a sieve.

Its not how well you do something,
Its how well you look doing it!