You can do this with the Rank System and a modification made by amykhar as opposed to hacking the usertitle system
You create 2 usergroups, Male & Female: By default, you select the "Registered" usergroup to be "Male" or "Female", and then create a profile field - You then use amykhar's hack to alter the user's usergroup on registration depending on what they choose, Male or Female...
For the profile field, you make it as follows:
Title: Gender
Description: Select your Gender; Male or Female
Options: Male
Female
Set Default: No
Display Order: *Leave as is or alter to your liking*
Field Required: Yes
Field Editable by User: Only at registration
Private Field: Yes/No (whatever you want)
Field Searchable on Members List: Yes/No (whatever you want)
Show on Members List: Yes/No (whatever you want)
Now Save it
Now goto the User Rank Manager, and add titles that correspond to postcounts for the Male and Female usergroups
Chris