As far as I know if you're only interested in class A all the time you mihgt have to use only one amp. As far as Cairn integrated goes it has good active preamp section plus you can use it as a headphone amplifier too.
If you want to experiment with both in class AB I guess they can work in vertical biamplification but most likely you will need to add extra volume controll for your poweramp.
If you want to experiment with both in class AB I guess they can work in vertical biamplification but most likely you will need to add extra volume controll for your poweramp.