Maybe this one? http://www.ebay.co.uk/itm/381098138635?

When I researched 6040s I decided I wanted ballscrew (not trapezioidal screw), and I wanted a control box with individual motor drivers rather than a 1 board solution. I don't know if those are options on 3040s

Someone else will tell you how suitable the 230W spindle is for aluminium (it might be OK?) I bought 800w watercooled for doing plastic.