You cannot ask people about mattresses or toppers or pads on the internet. We don't know if they will be too hot or cold for you. We don't know if they will be too soft or too firm for you. We damn sure can't put a metric on comfort or sinking as you may weigh 104lbs or weigh 28 Stone with both skewing things up greatly.

Go to a vendor with a great return policy and maybe get lucky on the first shot.