I want our members to be able to have access to creating their own site on SXDI.org...

I want our members to be able to have access to creating their own site on SXDI.org ... I see there are 2 ways to do this.

One looks like Pro Sites - which I have installed the plugin multiple times and it breaks the site - Error 500
after install.

The other way looks like WHMCS but I dont know anything about that ...
NOT even sure if I should be creating a new site (subdomain) and iunstalling Prosites by itself on that one ... We are using Memebrship Pro2 and want different membership levels to have access to "Create a site" and options - and be able to alacarte (upsell addon )

Basically here is what I want to happen and am asking as you are the gurus...

We want there to be an interface on ours ite that is available to members of different lkevels that has acess to create a site on sxdi.

All but basic members will be able to create a site xxx.sxdi.org...

Cant figure out as Pro sites crashes the site everytime I install it.

My user Info and login is the same and WPMU has its SA login as well.

Thank you so much!

Jonathan