Hi curlypearl! I wouldn't recommend drugstore flat irons just because those are the ones that are damaging to your hair. Ones that are tourmaline or titanium are usually good. A brand I was looking into but haven't tried is the ghd brand. Those are suppose to be really good, just have to watch out for fake ones. That's most likely going to be the next one I purchase though. I had a chi, a lot of people tend to like it, however, for me personally, I felt as though my hair was poofy after using it. I also had a Babyliss (nano titanium) which only runs for about $40 on eBay. I received compliments with that one, however, it broke after 7 months, and I just sent it back to the company today for the warranty. So, for something with good results and price, I'd recommend the Babyliss out of my experience.
As for heat protectant, a good drugstore brand I use is Tresemme Heat Tamer Spray. It's efficient and cheap! Another product you should look into is Chi Silk Infusion, if you buy this item from the store it is really pricey. I'd recommend getting the 12 oz off of ebay for $25. It can last you to over 9 months depending on how much your going to straighten your hair! You can also try out the 2 oz for under $10. It leaves your hair silky and smooth.
Also, just a few tips when straightening your hair: -Go through a strand of hair with the flat iron fast instead of slow, if you have to just go over the same strands a few times- it's less damaging that way. -Never straighten hair when wet! -Remember to section hair before flat ironing.
Hope I helped!!