Mast-mounted sector antenna(s) should work OK ... the usual stuff applies for line-of-sight, etc.
A bridge would work OK too ... a dual band 1230/40 where the "b" band feeds the clients and the "a" band is the "backbone" link back to the main site. This is basically how Cisco and Nortel are implementing their "Mesh" solution.
You "probably" don't want to run 802.11g to the clients here (using the bridge), every client after the first would tecnically be an oversubscription .... depends on the traffic patterns, activity levels and all the usual stuff.
Eleven Meg to the client for productivity apps and Internet surfing should be enough bandwidth.
It's pretty much a toss up. Given the choice of either, I think I'd go with the bridge for most things .... maybe go with the mast-mounted sectors if more bandwidth (than 11Mbps) is needed.
Mandatory disclaimer: A good site survey would likely give you the aboslute information you'd need to make your best choice.
Good Luck
Scott