I've currently got a Netgear WNDR3700 running OpenWRT.  Recently my ISP bumped me from 100Mbit to 1000Mbit service.  I've found that the little netgear, while great for everything else, just can't process that much data from WAN to LAN.  I top out around 200-300Mbit, which looks to be close to other tests I've seen on the web.

http://www.smallnetbuilder.com/lanwan/router-charts/

The r7000 that's at the top of that list doesn't look to support OpenWRT.

Can someone recommend a router (that has wireless builtin as well), preferrably sub 300$ that can process this much data through the firewall?  I think I'd be happy with anything over 850Mbit at this time.  I tried using a mini computer (fit-PC2i) and was only able to get about 450Mbit throughput.  When connected directly to the ISP with no router, I can get over 900Mbit easy.  I'd prefer not to have to build a separate machine just to be my firewall, but I'm not sure what my other options are at this point, that allows the level of configurability I need that OpenWRT supports.

There's no such router running OpenWrt. Some routers with a hardware NAT in the switch chip can reach almost gigabit speeds, but HW NAT is not supported (and won't be in the near future) in OpenWrt. Something with a dual-core Atom would probably do it.

Asus RT-N56U with custom firmware (non-wrt unfortunately) and hwnat enabled can handle up to ~1200mbit throughput (up+down) with DHCP/PPPoE on the WAN side. It is one of the few routers with 2 separate RGMII interfaces on the SoC as most of the devices use single interface and split traffic via VLANs.