Which hair straightener should i get?

I'm a little torn between the Ghd and the sedu. I have thick,long,curly, orange hair that is quite hard to straighten. currently i have the CHI and it used to work pretty well, but i've had it for a while and need a new one. I'm looking for one that is fast to straighten my hair, does minimal damage, and leaves my hair silky and smooth. i also am not going to be using it for curling, only straightening. which would you recommend? thanks!