Can you please advise me on what to look for when buying my friend a straightening iron as a gift?

A friend requested a straightening iron as a Christmas present. I just looked at Amazon because I thought the reviews would be helpful. However, I see there are different sizes, plates, professional vs. non-professional, brands from Babyliss (professional) to Con-Air (non-professional).

I have never used a straightening iron. Please recommend what’s good and what to look for.