I do not understand how you can buy these amps in under $2500, but I am guessing you would be going the used route. In that case try to find a Symphonic Line RG1 MK4, it will probably end your search for a power amp for a long time to come (till you have the funds for a higher end Symphonic Line).
BTW, the RG1 is stable at 1 ohm.
BTW, the RG1 is stable at 1 ohm.