H2PRO Allegro Ceramic Flat Iron 1 1/4" or BaByliss PRO Nano Titanium 1 1/4" Straightening Iron for curly haiir?

hi i have curly thick hair. it is pretty long too! i currently have a royale iron and it leaves my hair looking unhealthy. i want an iron that leaves my hair looking naturally straight, silky and smooth. also that leaves my hair straight all day. which one of these would you recommend or which iron would you suggest to me? please no chi's i don't like them!