hi. OK. to answer some of your questions. Ethernet boards use an Ethernet cable not the parallel cable and work better with lap tops due to the way the signal is pasted to the board. as you may know laptops are set up differently then desk top machines, battery saver being one of them, which will upset the internal clock of the laptop. and its this internal clock that the cnc works on. people use old desktops running windows xp or 7. because it allows the use of the parallel cable, windows 10 will not, but will run an Ethernet board. most people I think make their own cnc conversion, shop items in the uk are very expensive. the cheapest I machine I know of is the proxxon mini mill which as the motors etc fitted but you would still need to buy the boards to talk to the machine. Its not cheap this cnc stuff.