Would you mind providing more information on the DC barrel plugs and where you got them?
They are 2.5mm x 5.5mm DC Barrel plugs, the "short reach" or 9mm long plug . I got them from a local electronics retailer (Surplustronics), which unless you are in Auckland, NZ, won't be much use to you :|
The wire I used is "0.33mm^2", I would have used 0.5mm^2 if the had it in stock, though.