Hang on hang on hang on Crispy. Dont waste your money at B&Q yet
I used to make pierced laminate doors,(which gives sort of a panelled effect) the sort that Dave is on about, by the hundred, when I worked for someone else. This was done on a cnc router (about £60k worth), using standard carbide tipped cutters. All this talk of MDF blunting cutters is a load of buttocks. if you use a decent quality cutter, at the right speed, you will be fine.
As for getting around the use if a cnc, what i do now is use a plunging profile cutter, (I think its made by CMT) that has a bearing the exact diameter of the cutter attatched to the shank above the cutter. Then all you need is a template the shape of the inside panel, some double sided tape, and away you go.
Other than that. it is quite possible to create a standard frame and panel door using MDF. The ony difference being you have to use dowels or biscuits, instead of mortice and tennon joinery to construct the frame.
Hope this helps
Doughnut