I have a king size Spring Air pillowtop that I bought from Overstock.com 3 years ago. I am unhappy with it because it has formed some serious grooves where my wife and I sleep. I've considered buying a new mattress with a topper but to save some money for now I have been thinking about removing the pillowtop and using the spring part of the mattress.

If I were to cut off the pillowtop, which type of topper should I use? I tend to like a cooler room when I sleep and I am worried about the excessive heat from a memory foam. I get hot easily. Should I be looking at a latex topper? What is the thickness I should get? Should I get both memory foam and latex toppers?

I've also heard about making your own mattress from scratch, getting a foam base and building from there. Do you think I could do this for under a grand?