Cannot View Original clients source IP

Your options are limited due to the fact that the web servers do not have a default route back through the BIGIP. As a result you must SNAT, which causes the traffic to assume one of the addresses from the BIGIP. As Pawel mentioned, you can enable Insert X-Forwarded-For on the HTTP profile, which will insert a header into the communication, that the web server can then log. This can be done natively on most web server software, though on some older versions of IIS it will require an ISAPI filter.