Are you looking to build something permanent?

Skatepark
You may find a Sidewalk Skate Site goes so well, a more permanent solution is needed. In this case the next step would be to build a skatepark in that location and make it a new home base to launch more Sidewalk Skate Sites from.
To build a park go to www.splinterskatepark.com and join their network. They will provide everything you need to get started and will work with you for the long term.

Skatepark Ministry Format
You can still use the same weekly message as you do for your Sidewalk Skate Sites, but you may also want to consider launching a different ministry format for a permanent location.

If your skatepark is independent from a church you can launch it as a ‘Skate Church’.
A good model and resource for this is in Portland. www.skatechurch.org 
If your skatepark is part of an existing church, you may want to implement Skater Bible studies, independently from any youth group. Skaters tend to be a breed to themselves that don’t quite fit with the typical youth group.