For Samson amps and all other really low priced amps, Have you Ever heard about too good to be true? i would get a Berhinger EP 2500 or 1500 or have a look at the Tapco amp same quality as the Berhringer if tight on budget i would not get anything cheaper unless or are looking for trouble.
Samson amps are fantastic bang for buck, My Samson servo has a Toroidal power supply as do most of there amps and that makes them very clean and efficient.
I run mine bridged into two channels and have 240watts each dreiving 4 ohm speakers and have never had any problems.
I have used Carver, QSC, Adcom, H&H, and several other pro grade amps and the Samson has preformed just as well if not better as it has no fan to make noise.
Well, this one here is bridgeable to 600watts into 8 ohms or you can go with this one the SX3200 - Power Amplifier. At 1100watts per channel at 4ohms
There are a whole bunch more here from Samson's website
They have been in business for at least 40 years and make all sorts of Pro audio gear.