Eggdrop has a built in greet feature. It might not be advanced as you are looking for, but it's close. There are also some pretty cool greet tcl's around in the tcl archive. I learned the hard way though, that greet scripts can impose a flood risk to your channel. IE; one good join flood, and your channel is in for a disturbing ride!
Unless someone knows of a greet script with built in flood protection? I could never find one, so I just gave up on greets. I dislike having to kill my bot off the network to get him to shut up after a script kiddie visits. Maybe someone knows of one with flood protection, and we can both be helped in some form?