Nice!
I have a culture that sadly just died due to neglect (blame a holiday in Sri Lanka). But I think it's time to start up a new one along your lines - that kilner jar is looking rather lonely.
If it helps, this recipe has done me really well:
150/190/150 mix - use 290g for a standard batch (2 large loaves or 4 small)
980g strong white flour
50g light rye flour
21g salt
530g water
12h refresh, 4h first rise/ferment with stretch & fold after 2h and 3h, 2h second rise in a proving basket. Use stretch & fold rather than knocking back.
The 150/190/150 mix gives a really nice texture - but the it's up to you how close or consistent you like it (I know a lot of people prefer sourdough to have a much more open texture!)