When threads get this long, I do tend to just “read all” on the OP posts to make sure I haven’t missed updates. So I will have missed some of the “flavour” of responses. In the first instance, I don’t think you should automatically expect a female-friendly response, this is MN after all !
I am kind of struggling to pick apart your posts and what you actually want, so apologies if I go off at a tangent that doesn’t fit in with what you’re asking.
As a quick overview, I’d say that your current set-up is not working. A £300k combined income is great, but if it’s not bringing you happiness then it is definitely not worth it.
You need to figure out what would make you happy. As in have a really serious discussion between you. Otherwise it’s possible that one, or both, of you are going to burn out pretty soon.
With regards to kerb appeal of your imagined home - why does this matter so much? If it’s going to be your family home for years, focus on what’s inside the home.
Imagine, for one moment, that one of you gave up work voluntarily. Or, hopefully not, that one of you became ill and needed to give up work. You’d still have £150k pa which is way more than many households earn.
You could easily move out of London and find a lovely home on one salary. Find somewhere with train link into London for one person - and the other finds more local work at a lower salary, but upside is more time to focus on your children.
As an example, Manningtree (in deepest, darkest Essex) has trains direct to Liverpool Street in around 50 minutes for the person working in London.
The main thing you need to do is agree between you what is REALLY important to build your best life. Personally, I would rather one high earner at £150k and a more chilled home life as a result of that. I do realise that this creates an issue with regards to ambition for both parties. But I’m of the view that life is very short and that optimising your home/personal space is more important than flogging yourself to death for sub-optimal home life.
If you plan your search well, and don’t over leverage, you could find the perfect solution even on just one wage. £150k on its own is something that plenty on here could only dream of. You are in a great position to create the best life for your family, but you both need to seriously think about what is most important.