I have had side by side refrigs, top freezers, and bottom freezers... I loved my sided by side, IF I have room for a nice large one.. other wise the freezer tends to be to narrow..... over all I LOVE my bottom freezer..
As for the mattress, my hubby has several back issues, includeing blown discs, stenoisis of the spinal colum , several nerve conditions, and a major problem with pressure areas. I too have back issues. We have a termperpedic.... it took a bit to get used to .. but we love it.. Hubby especially sleeps so much better on it. I have prev owned a sleep number, it slept well, however, mine was older and the newer ones might be better.. my objection to these were the " blower" was noisy. I didnt like the idea of having that running all the time. I've had electrical fires before from leaving things plugged in and running.... but I did sleep well on it ( this was before hubbys time with me... so he never slept on it)
If ur refrig is still functioning, I'd opt for the mattress...... u will feel so much better if u get a good nights rest...