What size bed do you have room for and prefer?

The room is 5.60m x 2.80m, with the windows on the far wall. The floors will be light bamboo, from Costco.
I currently have a full-sized bed, but want to eventually upgrade to queen. As for space: if the bed is under the windows, a queen is fine. If alongside long wall, I could probably fit a king. But I worry that the room is too narrow fir a comfortable walkthru along the foot of the bed.

"Built -ins"!! If you have a friend(s) who have scrap wood, tool, creativity, and Time,
let them 'have at it'!! I "see" a streamline combo of drawers an shelves under those windows:
Keep the design simple, natural. Multifunctional storage and decor!!

Funny you should say that, @pjro: I was watching an Antonio Treatment rerun where they made suspended cabinets from reclaimed wood and was smitten with the texture.