You may have to wait a little bit for accessories and enhancements since the E60 (and respectively, the E90) are still fairly new. What you've found already is probably what's out there at the moment. Not a huge market out there because most people lease these newer cars and don't wanna mess with them. But there's a handful of things at bavauto.com if you haven't been there yet.
Anyhow, welcome to the forum, let's see some pictures!