Hey Suckitbitch,
Custom is the only way to go!!!
But if you want a script to test the waters with, I would suggest
http://www.e-classifieds.net/products/personals.html
It's a solid script, from guys who know how to build a script that gets a lot use. The main problem with this script is your limited to about 10,000 users per catagory and they will not let you remove the copyright info. Other then that it works great.
Cheers,
BOOM