Well from I can tell, couldn't find too much info on the Revox, but you have 2, 2 channel amps. That only gives you 4 channels to power your 5 speakers, so somewhere you are going to need one more amp.
As for using what you have, the 2 Rotels are easy to hook together, you go from the front left and right outs on the 1066 to the ins on the 991. Since the Revox is an integrated amp I'm not sure what inputs you would use, I would imagine and Aux, but I'm sure someone here will know more then me.
Good luck.
T