Can I buy a compact washing machine no wider than 500m?

Hello. There isn't one as far as I'm aware. No one can produce an appliance that's much smaller than everyone else's because they wouldn't be able to fit all the parts inside - especially with a washer dryer. Historically there have been the odd "slimline" front loading washing machines that were a lot less wide but they never last long (not enough demand) and they always had greatly reduced wash load capacity as they had to have much smaller drums. I have an article about Washing machines and associated problems with sizes which explains it all.