While I am partial to NAT Audio since my firm also imports the line, I would like to suggest doing some research on this incredible line and more specifically on the model called "Generators" that can run any loudspeaker from 2ohm up to 16ohm and is 180wpc into 8ohm and 240wpc into 4ohm. They are within the price range of what you're looking to spend.
www.nataudio.com and www.musicalsounds.us
Good luck
www.nataudio.com and www.musicalsounds.us
Good luck