Guest bed: what's comfortable, cheap, medium-plush, and fits twin bunks?

Howdy y’all! It’s been a hot second.

We have a bunk bed that will be used for overflow sleeping. Sometimes, my husband and I will be overflow. So I would like something semi-decent. Problem is, the budget is already stretched beyond thin, so we need to really keep the costs down. Also, I absolutely despise memory foam. That might be too mild a statement. I want a bed I can sleep on, not a bed I sleep in.

We’ve got latex (or latex hybrids) on all our other beds so clearly I’m a fan. Since the beds in question will be rarely used, I’d be okay with synthetic latex or polyfoam or hybrid or even the right coil.

What I need to figure out is what mattresses fall into these parameters:

  1. Twin size
  2. At least one has to be top bunk-compatible, so not over about 8 1/2".
  3. Not too heavy
  4. Comfortable for all kinds/builds of sleepers, or as many as possible
  5. Doesn’t sleep hot (we’re in Texas)
  6. $300 or less

I had been looking at the Ikea mattresses but I’m afraid they’re too firm, from the reviews I’ve read. Also they don’t seem to offer latex mattresses anymore?

The mattresses will be going into an Ikea Mydal bunk bed frame.