Lucky for me, I noticed that I'm all out of P-channel MOSFET's... need to order some!
Someone told not to quote him or her on this, but it seems true enough:
"When triggered, a p channel mosfet connects the input on the load to the positive source whereas an n channel mosfet connects the output from the load to ground or the negative source."
This means my N-channel MOSFET's doesn't work as a current supplying unit and would have rendered the whole device "useless"... The pin layout is also switched (source becomes drain and vice versa) so I need to redesign the board slightly.
Things you notice when trying stuff on a bread board! ;)