Mattresses - Hemnes Day Bed

Hi
I need to get mattress for an Ikea Hemnes Day Bed - I am not keen on Ikea mattress which I think are 80cm x 200cm.

If you have one which mattress brand and size did you buy?

Also, would you buy a memory foam for a guest bed or a pocket sprung or what would you suggest?

Thanks

I have this bed, I bought the suggested mattresses with it from Ikea and I replaced them with memory foam after two years. Still get reports of bed being comfortable, so I think it’s working out.