It would help to know the router that you'd be connecting to. Can you run inSSIDer on a laptop or some other wifi sniffer to find out what the router is? The typical bridging protocol is WDS, and it isn't as standard as one would like, so going cross manufacturer can lead to problems sometimes. Heck, even within the same manufacturer can cause issues sometimes.
That said, what I use for an inexpensive, but very fast, N600 router is a TP-Link WDR3600. I have a couple laying around. Two antennas, nice and fast. New only about $50, used maybe $35.
A couple of these
http://www.amazon.com/dp/B003CFATNS/?tag=snbforums-20 or a couple of these
http://www.amazon.com/Super-Power-Supply®-WZR-HP-G450H-WHR-HP-G300N/dp/B00DTWTXTK/ref=sr_1_16?ie=UTF8&qid=1432846376&sr=8-16&keywords=2.4GHz+yagi would set you up. I'd be inclined to go with the panel antennas as they'll be a little easier to work with since they aren't as narrow focus.
That said, you can always get the router, play with the shipping antenna orientation and see if you can get a good connection that way. May not need bigger antennas. You could also just get larger dipole, but that may not be as effective.