Not sure what you mean by rack vs console?
Your avr has only rca pre-outs so rca cables from those to the inputs on the power amp.
Amp needs a certain level of voltage to perform to rated output, spec is called sensitivity, often in range of 1V-2V. Your Marantz pre-out voltage will likely be fine with all of them.
Never used a power conditioner in 45 years, amps do fine with wall outlets, they can handle swings in voltage just fine usually.
12V triggers are fairly common and believe your avr is already equipped with such; an alternative is a smart power strip (what I use for some amps without a trigger)
Same way you calibrated using the avr's amps alone (re-run Audyssey or whatever you did before)
All those amps are fine, they differ somewhat in power and price so choose a combo you like. Personally I'd also look at Crown XLS amps (I have several). You can always use an spl calculator to get an idea of what your power will translate to at your seat...
http://myhometheater.homestead.com/splcalculator.html