Thanks for all the info and side notes.
I'm powering LED spotlight bulbs - so there is a little transformer / buck inside the bulb. No need to limit the current myself.
After comparing several datasheets, I've decided to go with IRL2203N for the FET.
It's cheap enough, has low voltage at the gate 1v - 2v, low resistance and 116A rating.
It's actually the only one I saw at a low price that will use less power than a SSR. - SSR's look pretty efficient, and seem to outperform the other fets at 2A +
Thanks guys