Is there a billing, server/asset management type tool out there for dedicated hosting and possibly managed services? Such as something that perhaps tracks inventory, and allows the "customize your own server" type features?

I think Ubersmith does that. If they are still advertising here, you will see the ad at the top of each thread. My firewall blocks ads, so I dont know if they are still advertising..

They are... *I* haven't blocked the adds yet... ;)

I would prefer a piece of software that can be hosted locally... as far as I can tell Ubersmith will only allow you to use their software if you host it with them, and frankly I wouldn't trust a competitor (Voxel) to host my billing system.

Also, where is there an example of a "customize your own server" type feature being done with Ubersmith? Seems to me, there isn't a feature like this.