re: What router should I buy?

Layabout's suggestion for the ASUS RTN66-U is solid. Pretty much best in class. Strong signal with amplification, easy setup, reliable. It's N900, but I'd recommend it over any AC router at the moment, until we start seeing the true potential of 802.11ac, like with ASUS's upcoming RT-AC87 4x4 MU-MIMO router, which I'd consider a minimum purchase for any sort of "future proofing," and only if you know you'll be getting some serious new hardware with adapters to take advantage of the available spatial streams, and only if you tend to heavily traffic your local network. That's going to be an expensive router at launch. $270 I think.

The RTN66-U is $120, though, so if you want to go a little cheaper, the Linksys EA4500-NP is decent and can be found for under $100. I'd get the ASUS, though.