I have struggled with the same. I have put dd-wrt on a couple of clones and ending up bricking them with updates or modifications. I have two suggestions. Mikrotik has just come out with a high power ap / router for under $100 bucks. Their routeros is linux based and the new ap/router has a usb port also. I have had good luck running hostapd on a linux server. I presently use one of the high power (EPI-3601S) available from Amazon or Newegg and the latest version of Ubuntu server edition. Works great however, this card doesn't have wireless N.