What kind of mattress should I buy?

I need a new mattress, but I’m overwhelmed and confused with all the options that are out there. I am very curvy and so that makes me think I need a really soft mattress. But, I also really love sleeping on my stomach and I would think that a firm mattress would be better for that. (I’m trying to break the habit of sleeping on my stomach, but it’s hard to!)

My sister mentioned a Sleep Number bed, but I don’t know. I thought maybe a memory foam bed…but I don’t have anyone who sleeps next to me and aren’t those mainly about not disturbing your partner? The innerspring mattress I have now lasted about 5 years and now has a bad bow in the middle. I wake up every morning with a sore neck!

Help! I need some experience or advice!