Do what I did. Call a tech/sales rep at Sweetwater. Couldn't be nicer and more thorough if he tried. The first purchase was a Crown XLS 1502. Really couldn't be more pleased with that unit. Quiet and tons of headroom; ran a set of Ohm Walsh 5's like nothing. Those have been sold and replaced by a well loved pair of JMLab Mezzo Utopias with a little preamp and a Crown XLS 1002 which to my ears produce nothing less than aurel bliss.
Good luck.
Good luck.