The question really is how do you power a HP e-PC without using the brick. Because the e-PC only uses a direct plug/brick and not a 20-pin plug that goes to a power supply like other PC's or VIA mini-ATX boards.
How will you plug a M1-ATX or M2-ATX to the HP e-PC if it doesnt have a plug for a 20-pin ATX plug? that is the question...!!!