By disabling the that a item can be bought you get a similar functionality.
But you have to give the user every item via phpmyadmin
Or if you can code, you could write a php system that lets you assign all the vip items with a single click to a user (is very easy to do).
Another option would be to wait for the next version of the store webpanel, there might be a feature to add items (but I am not sure when I have time to add it);
Some people would just rather a mod that gives perks to a specific flag instead.