Would any of these work at both ends of a 2x wireless link?

Rb450g
Rb250gs
Rb750gl

The problem is I'm transferring a large amount of files ptp across a convention center, I was running wire from one end to the other, via gb Ethernet the upload took about 30 seconds but over wireless (nano station 5m's) the transfer takes 3 minutes, I only have about 3minutes to complete the transfer, so I would like to speed it up a bit... I'm hoping adding two mikrotik products and two more nano's will help lower the transfer time!

rb450g is ok

Thanks, is that the only one out of the three?

Will be faster if you need more speed..