For broadcom, likely the netgear r7000 or asus ac66 would be your best bet. I've seen the r7000 refurbished on ebay for a bit over $100.
If you're willing to try atheros, I've had a lot of success with the TP-Link Archer C7. I've setup 12 now for various people/places this year. 10 are currently wall mounted. Depending on your connection speed, the 720mhz processor may or may not be enough. They handle anything I've thrown at them though. I've read reports ranging from 100-220mbits max NAT throughput on DD-WRT. WIFI coverage is outstanding, and it's less than $100 even when it's not on sale. Just avoid V1. Get V2.