Creating Custom Roles for use on a WordPress Multi-site Instance?

We have a large site that consists of a number of smaller websites. We are looking at replacing our current CMS with WordPress.

The only problem is that we need to create a custom role (kind of in between Editor and Administrator) and make it available to all sites in a multi-site network. I have looked at a couple of plugins that work well on a single site, but none seem to work on multi-site.

Any recommendations? This is the closest thing I have found:

• WPMU Roles and Capabilities Hacks Plugin