Multiple public IP behing PIX 501

Yes, it is possible.

Thanks a lot :-)

Yes, that is not a problem. Do note, though, that the PIX itself will be at 62.bbb.xxx.yyy/30 for the purposes of traffic that terminates on the PIX itself. For example if you have a VPN connection, the VPN peer will need to use the actual outside IP address: you cannot tell the PIX 501 [1] to accept VPN connections on one of the inside addresses. [2] [3]

-other- PIX 5xx models, but not the 501. [2] with the exception of a VPN connection used to talk only to the PIX itself and not to inside" [3] PIX 7.0 might have different restrictions, but PIX 7.0 does not run on the PIX 501.