Receiver


Hi all, 1st time ever to any forum and full disclosure I am a total novice in the audiophile world, that being said, I am looking for recommendations for a 8K receiver to power the following unpopular speaker in the USA, Vienna acoustics. I have a total of 7 speakers (4) Grand bookshelf 6ohm (2) Waltz 4ohm and (1) maestro center channel 6ohm. I am currently using an older Marantz SR7005 but since I purchased a 4K TV I am looking to upgrade!
thank you in advance 
128x128tjl441
I wouldn't put any consideration into "8K" stuff.  It's really just the next marketing gimmick to "sell" consumers into buying new equipment.  Realistically, in some situations, you really don't even need 4K. 
Am I doing something wrong? I have a 65" 4k TV and tube amps in 2 channels with a sub...
Another way to go would be to get separate pre amp processor and multi channel amps.  I use a Parasound 5 channel amp in one system and the Anthem MRX 520 is basically a preamp.  In my other HT system the Anthem 520 drives all speakers.  Miller’s remark that a receiver might have to much going on under one bonnet is an extension of the same philosophy that in two channel, separates work better than an integrated amp or amp/DAC; there is something to that but in practice there are excellent sounded integrated amps and AVRs