My hair straighteners must be 10yrs old and have given up on me. Looking at replacements on Amazon for speed of delivery, and getting bamboozled by the range of features and prices. Negative ions. Infused with Moroccan oil. All different brands, £20-200. What do I really need? Is it best to go for a name I've heard of or does it make no odds? I've got long thick straight hair, mainly use them for smoothing.