' comes to mind as one you could use to test/burn. 'Memtest86
' can be used to test your memory. By changing memory timing and conditions you can find out how far you can push the system.
There are several hdd diagnostics that could be used. You could even use your hdd manufactures diagnostic set to test the hdd. If what you are looking for is a general burnin or test media then there are several commercial sets available for $$$.
If you do some 'google:linux
' on over clocking you will find a lot of utilities for burn in. If your not OC then the utilities can still be used to test/benchmark. If it ain't broke don't fix it!
You can always just use the machines and see what happens.