Right way to shut down ESX with APC UPS

Hi.

About my setup: I have about 20 servers across 3 different ESX, to these to ESX server are 2 APC 3000 UPS (With management card) connected

I think I have searched quite a bit and right know, as I can see there is 3 solutions:

• Install the APC client on all servers manually. (What about the ESX?)
  
• Make a perl script thats shut down the virtual machines, but it cant start them again.
  
• Make a vMA server thats have the APC software on it, which remote send a shutdown signal to the Virtual Machines and ESX. (Again what about startup and ESX servers).
  

Thanks.

Regards Nicolai Pedersen