What hair brush should I use for my hair?

So I have shoulder length hair and it is not too thin and definitely not too thick. It is not super straight but it's okay. Whenever I use my straightener my hair gets 60% straight. It's a conair brand one. My hair is usually smooth but I really want it to be more straight.

I was looking around for brushes and I found many different kinds. What kind do you recommend? I was thinking about a paddle brush with boar bristles but I'm not sure. I want a brush that helps detangle well and efficiently and I want one where my hair will become straight from that. Would it be better if it were all boar bristles or boar bristles and nylon?

I found also different brands like MP, Denman, Spornette, Tangle Teezer, and Wet Brush. I know Mason Pearson/MP is the best but it is way too expensive. I was thinking about a Denman or Wet Brush but I don't know which one to get. Again, I want one that detangles efficiently and where it will be straightened. Even if it doesn't straighten, I can use my flat iron so no biggie.

Last question is where can I buy the Denman Brush? I know that the Wet Brush is at Target so that's easy to find. Any local stores to find Denman Brushes? I live in the Bay Area.

Thank you so much! :)