you can find this anywhere, it is pricey though but it is so worth it, I have had this for a few years and it still works great. I too have frizzy wavy hair. I did do research before buying this straightener and it was rated as one of the top straighteners out there
Anything with ceramic plates. Real ceramic. It will smooth hair and keep it shiny for the most part without it ripping the hair out. There is a spray, it's called SexyStraightHair. You spray it on your hair right before straightening it. It helps keep it protected from heat because in reality, anything hot, no matter the material will ultimately damage your hair.
Look into going to Sallys for that type of straightener or any hair product place.
Use ceramic straighteners, they are usually around $20, I was told to use them when no other straightener worked...It works well and you can adjust the heat to where it won't damage your hair...way better that wasting a S#!tload of money.