Not all Macs do the internet restore.
You could invest in TechTool, it's handy sometimes, though not really the greatest. You can also use Memtest86+ or Eurosoft PC Check on Intel Macs for hardware tests (I find the apple hardware tests unreliable). Beyond that, it's REALLY useful to have a bench mac for a number of reasons.
Our mac repair software is just this:
Tech Tool, , Carbon Copy Cloner, SuperDuper, Disk Warrior, Data Rescue 3 and all of the OS X versions from the past few years