Nice approach also notebooks with broken screens would be a good option for something like this.
Nice.
Do you have any guides you wrote or used that you can recommend? I'm looking at getting SmartOS set up at home as well, but I know I've got a lot to learn.
It sort of just works. Get yourself a big USB thumb drive (I use 8 and 16G) and boot off it. You'll answer a few questions to install.
I like the Thinkpads because they are so cheap ($200-300) gets you an i7 and 8-12GB RAM. The CPUs are compatible with SmartOS for KVM guests.
All that said, I really should write a definitive guide of how to operate SmartOS coming from the linux ecosystem.
The whole cluster idles at 150 watts and each node is backed by it's own dedicated battery. Upstream I have about 4 hours on an APC unit which also protects the router and modem from outages.
My own little cloud for under $1,200.