I don't have any direct recommendations, but I can assure you the 2.4 spectrum is severely overcrowded. 802.11A will give you better results.
Try a .A access point, much better. You won't be able to penetrate as much but you will most likely have much better results.
Buffalo seems to be very popular, I don't have any direct experience.
-edit-
I do have direct experience with the 2.4 spectrum used by 802.11B/G. It sucks, it's full of noise because of all the other devices using it. 5 Ghz/802.11a is wide open.