I think there will be a problem with percentage of load. Linux load is not only about CPU, but others resources are calculated too. Unix systems traditionally just counted processes waiting for the CPU, but Linux also counts processes waiting for other resources — for example, processes waiting to read from or write to the disk.
On its own, the load number doesn’t mean too much. A computer might have a load of 0 one split-second, and a load of 5 the next split-second as several processes use the CPU. Even if you could see the load at any given time, that number would be basically meaningless.
There is nothing like 100% load. I can display current value of CPU usage, but not load recalculate to % .
And disk usage is similar thing. There is percentage of single partition, or multiple partition, but what about unused part from volumegroups or disk part used by swap?
I can help to you redefine your needs and write correct script for this :)