Plastic Enclosure Design

I build power supplies for different hobbies. I need to enclose the power supplies into a presentable case that looks like a finished product. This case will have female ports to plug a 4mm plug into. The dimensions of the powersupply is Dimension: 28 x 8 x 6 cm approx. It has a power plug int he back of it but internally in the case will be able to wire up a y cable to both powersupplies that is powered on by one external power connection. Sample case 2 shows the kind of ports this case should have built in to it.