A cheap low powered netbook will work well for this. You dont need a lot of cpu power and 2gb ram is plenty. Connect to a usb hub if you need more ports.
I understand we haven't seen the design yet. If we were going to use the laptop, how many USB ports do we need? Each SC will take a USB port?! Can we join SCs together?
Each SC Single will most likely use 1 USB port. They don't use a lot of bandwidth, so using any
USB hub will work just fine to connect several SC Singles to one laptop.