Have you looked at Blended Beauty Straight Pearl? I know of a few posters on MUA, who swear by it. I believe it's CG, but works well for straightening.
The other thing I've found, now that my hair is in better condition from taking care of it, is that I can straighten it easier with a round brush and a blow dryer. I don't really have to use a flat iron at all, but I am more wavy/curly then full curly.
Chaz Dean (the founder of Wen) has a great video on youtube showing a blow out. I don't have the link, but just google it on youtube. It really works. And I do feel a dryer and round brush are way less damaging than a flat iron, if you can get that to work for you.
Hair Type - medium to fine texture, high porosity, lots of it, type 2b/3a