Are you dead set on a submersible?
I run an Evolution ESM 4500 and ESM 5500 pumps on my larger tank. The ES series is cheaper but louder. The ESM uses an american made marathon motor and is very quiet & reliable. Low power consumption as well.
http://www.highdesertkoi.com/pumps.htm
^ Steve at highdesertkoi is a really great guy I've dealt with twice now. He tests all the pumps he sells before shipping them out.