Hi, I am not familar with the lighter, but we are printing also on metal ADA signs.

I guess all UV printers can print on the metal material but you would need to apply primer as what we r doing. I believe all the models are applying the same ink system, so they should be the same for output I guess.
You'd need to consider about the printing qty/daily base as the printing speed varies from the printers. I did have experience printing for my sister's team for pens, my model 5000U, I printed 75000pens in in 8 days, not too bad for me.

If I were you, I would ask samples from the supplier first