I think we need to see this larger then only the server. I agree that if you just want a cpu graph, you can do it manually with hand-written scripts/files/...
But since linuxmce provides a lot more (dhpc, dns, proxy, firewalling...), we can take this up a higher level. If you put in tools like cacti, you can start monitoring your whole network/house. Think about all computers, switches, routers, power-meters... The key-element here is the user-friendly stuff. People need to be able to do it themselves, simple. With this, you gain that more people will use it, less people will ask you questions...
And it must be flexible...
LOL I see now, your looking for a magical do everything gui that records EVERYTHING you want with virtually no scripting/command prompt. Bwahahahahahah!!
The solution I provided (if you read the bash script) is generic, it'll work with ALL linuxmce systems (testing is needed) and if accepted by the Linuxmce gods, you do virutally nothing just install the package, and click on links in webadmin... It also does as you wanted; Intergrates into Linuxmce backend, looks through your database to finds how many MD's you have, and if they have HDD's it adds them to the graphing list.
"larger then only the server" - I wrote the script in about a day, and it is.
"And it must be flexible" - It is, I have a graph that shows downloaded weather reports and compares them with HDD temperatures.
"Think about all computers, switches, routers, power-meters" - it works with all snmp enabled devices, and those that you can generate scripted statistics. Again... written in about a day.
You've obivously just discovered cacti, and haven't had much experience using other related software... I have used most, and when your talking about flexibility and low overheads MRTG is better. I thought as a network engineer, you'd have used MRTG, as most larger networks do.
And with that I say "Your welcome", "Keep dreaming", and by all means prove me wrong with your working demo.