Hallo
The AE has an changeable front, so you can buy a black replacefront and change it with the original one.
You could buy the ultra version of the AS XT, but there will be no Different at the functionallity of the AE. The AE is a stand-alone-device. The advantages using the ultra Version are the build in watertempsensor and of course the possibility to control another pair of fans.
Of course you can shout down the system of base of the flowrate (sensor required), the tempreture of the water or any other value the AE gets from its Sensors.
Each Channel can handle 10W, all 4 together 30W. In Case you want to control to systems the fourth channelmode can switched into a Flowmeter.
I know my englich isnt the best, sorry about that.