I would recommend the 2800 but not the 1800 simply because it does not have enough power and runs on only 6 transistors per channel.
Because the two rack space amps do not have the huge capacitor load banks like the big CV 5000, it is best to bridge them for bass use in my experience.
Everyone seems to two ohm load on AVS regardless of the consequences. The CV is rated 900 to 4 ohms, so you can always try one, and if results are not good, you can move to two amps bridged. (one on each woofer) The price is certainly a good value. I probably own more of the CV amps than anyone else on the forum.
A Good amplifier requires a adequate power supply, It does not matter what the amplifier is capable of if the power supply will not provide the power required. Most amplifiers have under rated power supplies. It is up to you to make sure you get the ones that are
least under rated if at all.