R7900p AND EX800 or Second R7900p

So I have a R7900 as my base and i have a cat5e running to the other side of the house where i want to have up to 2-3 Gig Ports and Wifi with the Same SSID and hoping that it will all be managed as the same.  I had this set up with ORBI, but it was missing features that the NightHawk had so i moved to the Nighthawk, R7900.

I was thinking that i could add the EX8000 via the Gig port as an exteneder.  (I do not want to use WIFI MESH) it adds a little latency.

What should i add?  a second R7900 in AP mode, or a EX8000?  looks like i can get a second R7900 refurb for 159, vs the extender which is still full price.  

Can they be managed with one policy, and visability? 

Will Guest on the second Router or Extender be restricted from my lan?  As the traffic from the second device will be backhalled back to the base via Gig Ethernet, ... (does it trunk?)

Thank you for all your help