Sweet dreams are made of these: Reddit, help me improve 1/3rd of my life. Need help in purchasing a new bed.

I suppose a lot of it is preference, but I have had a firm mattress for a few years now and it's good, it's just that I'll be needing a bigger bed soon (currently have a twin I think).

I have laid on some sort of foam mattress before and it was amazing. Just looking for tips on where to buy a new bed and things I should be looking out for.