I would be inclined to find a good condition used audiophile amp.  I use a Carver M1.0t in my studio and would recommend one or two of these, or the M1.5t.  I've had a few of these early-generation amps and have always found them to be powerful, quiet, and reliable.  An M1.0t is is about the same price on eBay as a new Alesis RA500 and has about twice the power (200 WPC @ 8 ohms, 400 WPC @ 4 ohms).

However opinion on Carver amps tends to be bipolar (love 'em or hate 'em) so I'm sure you'll find plenty of people to disagree with me.  But they drive low impedance loads (down to 2 ohms) well and are bridgeable by design, so you can always add another and drive them in mono for lots of power.

Whatever you get, don't skimp on power, and make sure that you understand how the power is rated.  For example the Carver M1.0t is rated at 200 WPC with 6 dB of headroom, meaning it's capable of about 500 WPC peak or 1000 W mono.  A lot of prosumer amps are rated differently.  Speakers are typically damaged through underpowered, not overpowered amps.

I would not purchase a "cheap brand" sold anywhere.