My immediate thoughts fall to two of the watches that I currently own.
For a mechanical every day watch for under £1k look at the Damasko DS30. They are 39mm and also very thin so not at all bulky. The submarine steel case is very scratch resistant and robust.
If you are prepared to go quartz, look at the SBGX0** range of Grand Seiko's. 37mm with slim case so not bulky. They do come up for around a grand or so used. The 9F quartz movement is astonishingly accurate and has a theoretical service interval of 50 years. Good write up here: https://www.hodinkee.com/articles/se...ith-caliber-9f