Get a tempurpedic grand bed ($6,299), which is the maybach of mattresses and try it for 90-days. If you don't like it, they'll take it back with no questions asked and then you can start exploring inner spring mattresses. People that complain about the mattress sinking are usually the ones that purchase the bare bone models with just one slap of foam. Your room temperature and body heat transmission has a lot to do with the conformity of the mattress (bed sheets and clothing worn while sleeping). If you sleep with just boxers on like me, tempurpedic should be fine.
Make sure to purchase it through their corporate site as stores like sleepys offer only 21 days and ebay sellers are usually selling fake rebranded aftermarket foam beds. Give the bed a 20-30 day break-in period and you should be able to experience the full potential of the tempurpedic.
Side sleepers = nothing beats foam, especially if you have broad shoulders.
Back sleepers = anything firm will work.
Stomach sleepers = consider changing position dawg.
BTW, S&F is owned by Sealy's.