The stock firmware on the Asus RT-N66U does all you want.

I have the 802.11ac version, but I have told a bunch of people to get the 802.11n version when cost was an issue. Never had a complaint about either router.

I've been using Asus routers for years with DD-WRT and the hardware seems solid. I've been running stock firmware on these two newer units for about a year now. It does all I want, so I'm fine with keeping it.