The griddle that comes with it was cast aluminum, which is still great IMO, but not a cast iron one. I'd be interested to see how stainless does, it might heat up and cool down quicker than we are all expecting. Those burners are serious, so keep that in mind, so you don't warp the steel. Course will depend on thickness. When you fire the burners expect some hiccups. They routinely give an error (I forgot which) on light. Try it a couple of times. Watch them, and drop the panel down to watch the injector. One of mine likes to stutter start, and then when it lights, and oe time I did find a stray diesel drip that lit on the wrong side. Once it's going, it never has this issue. I still have two burners that decide they will go out and relight randomly, even after hours of use. Still haven't taken them apart. Running them for a day cooking will get the kinks out (or you'll know the issues). I think the MKT is an absolute blast, even though its more work than most think. Get a helper and make a day cooking for family or friends. You can also power those burners with some easy wall plugs. 2A 24V ones are cheap on the bay. If you are doing 1 or two, and testing it at home and close to power, it's easier than hassling with batteries. Have fun with it.
EDIT: And I haven't been down the jet fuel path, I run road diesel in mine. Jet is a little hard to get around here, even though I am a pilot, and know where to get it, they didn't like the idea, so as mine were bone empty, I ran road from the start.