Safari might work OK with the Cisco web set-up system, I don't know. Chrome, Firefox, Opera and Konqueror definitely don't work properly with it, or at least not with my version of the Cisco firmware. You might be able to borrow a WIndows laptop to do this?
Incidentally, other makes of WAP may work well for you - I can connect reliably over 80 metres with a Netgear WG602 unit and this unit's web-based admin system works with any browser. I only mentioned the Cisco units because they are know to work well over several hundred metres in open terrain, between two farms for example or between my house and a school 2 blocks away.
Andy