Actually, cable problems are not product related. I used to solder my own - still have cable and various 9 and 25 pin plugs for making them.
Once properly cabled systems that can be started via the serial port are extremely flexible. I manage 4 different systems - power on remotely, via serial cables - as this can be automated with "expect".
Here is an easy cut/paste script for powering on a POWER5/6/7 system using expect: HOWTO: POWER on using EXPECT