Hi TheSmiths and welcome back after five years!
Well that’s’ certainly a painful problem in all senses! Attempting to sleep on what sounds like sleeping on a floor, even briefly, can cause all sorts of problems in your muscles, joints, pressure points and back. It’s really a good looking piece of furniture, and it’s understandable you want to turn it from a dud of a bed into a dream!
Since mattresses are such a personal and subjective thing, it’s impossible to tell you what you need to purchase as a replacement. It really stinks that the company went out of business…although selling a great looking wood cabinet that has a ‘brick’ for a sleeping surface could be a tip as to why they went under.
First you need to consider the basics. As you know, the ideal replacement mattress will be based on the Stats (height, BMI, sleeping position(s) and any underlying health conditions) and the PPP (Posture and alignment, Pressure relief and Personal preferences). Thanks for giving a general average weight, that helps a bit to give a little context for the solution.
Since it sounds like you are considering all options, from latex to memory foams…you may want to read the the Mattress Specifications You Need To Know and how these compare to the Mattress Durability Guidelines, to see how durable specific materials are.
We suggest that any foam in a potential mattress has no more than an inch or so of lower grade foams (for memory foam no lower than 4 lbs/cuft for normal range weights, and 5lbs/cuft for higher range weights) and if polyfoam is used, with at least 1.8 lbs/cuft density, just to ensure you have support.
You need to determine what material, and the comfort and support that match your preferences for the replacement mattress; once you have that there are a number of Trusted Members of the site who specialize in custom mattresses to fit unique furniture, like Bay Bed & Mattress, Fox Mattress, and Texas Mattress Makers, among others.
You shouldn’t need to settle for a too-firm mattress, even for occasional guest use…and if you can put a little consideration to the points above, and reach out to a qiuality mattress manufacturer, you might find that you can have as comfortable a sleeping solution as with a ‘real bed’!
~ Basilio