Seiko 5 and Seiko 5 GMTs are great, but Orient is also a worthy contender.

Check microbrand atlas. A map with many microbrands(almost), including UK. https://microbrandatlas.com/

If you get any cheapish mechanical watch with a widely available movement (EG an NH35 or NH36), it makes more sense not to service it, and just replace it when (if) it wears out. That's what I do with my Seikos.

Seiko 5 is the go-to recommendation for inexpensive mechanical watches

A watch service costs more than a cheap watch, if you define cheap as under $300-500. If you get a Seiko or Citizen with a common movement, you can just have the movement replaced if something goes wrong. I’m not a fan of low end Swiss watches, Japan does them better.