Profiles in a profile, Social Networking Site

This weekend I'll be playing around with some of the social network softwares out there to see what might be able to be used for my goals. I'm looking for anybody who has any experience in social networking software. I've been looking at Elgg, Ning, and Pinax right now. Main requirement is to be able to setup profiles in a profile. Ex. Knife collecting social network site. User has a "profile" under his account that has multiple knives with stats on the knives that he can edit. If he puts up that he is going to an event then he will be saying what knives he will be bringing along and that will reflect on the site when people look at the event. Another main thing is to try and focus on location. Users/Events/Clubs will be searchable through location with in a certain distance.

Thanks for the help.