I have some questions about Herbal Essences products?

I'm in love with Herbal Essences hair products, and I've only tried 1 of their shampoo's. I tried the frizzness one since my hair becomes frizzy with all the heat styling I do to it.

I'm looking into trying another one of their shampoo's, except this time also including the conditioner. (I haven't used conditioner in forever). I was thinking about trying the Hello Hydration shampoo and conditioner so my hair will be silky and soft. I also wanted to try something to keep it straight after I flat iron it. I usually straighten my hair alot, so here are my main questions for anyone who can help me:

What Herbal Essences styling product should I get to help keep my hair straight/shiny?

Is Hello Hydration a quality shampoo conditioner? Does it make a difference in your hair?

What about the Long Term relationship split-end protector? Would that help my damaged hair?

I know I asked a lot of things but thank you so much for your help!!!