A good, clean, un-congested system monitoring app

Hey,
I'm looking for a system status/monitor app for mountain lion. I had a look through the App Store, but what I found was either lacking in features or had an interface which was congested an over crowded.

What I'm looking for is an app that will sit nicely in the status bar, maybe displaying info on CPU usage a battery and when I click it, I'll see more info.

The the info I'm interested is as follows:
- memory usage
- CPU usage
- battery status (charge, cycles, temp)
- accessories' battery status (info on Magic Mouse battery level)

If it can show network info (speed, ip, etc.) than even better, but that's not the main feature I'm interested in.


Thanks