Since you aren't able to run wires, how about powerline network? At least you would be able to connect two separate rooms and expand your signal through walls and lengthy distances.
I did this, and they work very well. I got 2 of the TP-Link TL-PA511 kits, connected each end to a gigabit switch, and run various devices on each. It was a lazier/easier way than snaking Cat6 through my walls and across my entire house.
I would still prefer Cat6 homeruns back to my office, but as a tie over, these work nicely.
As for a router, I got an Asus RT-N66U. I used this to replace my old Linksys and various Asus 520 routers, with 3 of them configured as access points, using WDS. Right now, it reaches anywhere in our house (2800 sq ft) and outside, but this is only one story. However, it's built on DD-WRT and there are custom firmwares available, so adding in a second for an extender would be easy.