I wouldn't recommend weekly straightening. I used to do that and my hair was dry and full of splits because of it. At the most, I might straighten my hair once monthly and wear it like that for a week. The rest of the time, I wear it unstraightened in a bun, pulled back, or gelled.
Minimal heat was crucial for my hair to grow and be healthy.
As far as flatirons go, I've been using the Jilbere ceramic for a couple of years now and I have no complaints. Working in small sections and cooling that section right after straightening it are a couple of tips to try out.