septillion:
That's what every MOSFET manufacturer does... :At least this seller tells you.
Was talking about dc-dc convertors, not MOSFETs. Martyn's suggested MOSFET should be plenty for the task, they are rated for (max) 5x the current he needs, so should not even need heatsinks, but I was worried about the dc convertor he found.
But you're not wrong about about MOSFET manufacturers...