You should spend the least amount of money on an AV receiver. Get one that has pre outputs for all the channels you care about. The power figures reported on the AV receiver are to be taken with a grain of salt. None of them hold up. Besides, if you are plugging in a dedicated power amplifier, that load is less for the AV receiver. Power demands are not continuous for the non primary channels
Is there some reason you are particular about Denon, Marantz? Why not a NAD or an Emotiva MR1L Av receivers? More expensive no doubt but you'll get more for the money in terms of performance