Always amazing how there is a 20-page discussion in the forum about an amateur draft.
If I have a budget of 750k, I don’t plan myself but have a professional do it. The worst thing here is that the OP is so stuck on their floor plan that they are "blind to their own mistakes." If you want to build like that, even a hack builder would suffice.
I see the danger that if the OP gets a capable architect, a rude awakening will follow. Because the professional listens to the room requirements and then plans accordingly. Of course, in coordination with the client, but usually the result is something different than what was originally planned.
I can report from my own experience here. We also wanted to adapt a prefabricated house manufacturer’s plan to our plot. After the brother (an architect) of a colleague looked at it, we realized our plan was nonsense. We then went to 3 architects and defined our spatial needs. Three completely different house types resulted. We stuck with the architect who, in our opinion, best met the spatial layout.
Originally, we wanted to build 2 full floors with a gable roof. It ended up being a flat-roof house.
Again about the budget: 750k including interior fittings are mentioned here. What should one understand by interior fittings?
You planned just under 340 sqm of floor space plus 34 sqm garage. I think the budget will be tight there.
We have 288 sqm of floor space and a 55 sqm garage. We are currently at just under 700k for the house alone, without land and interior fittings like furniture, kitchen, etc. The garden is, by the way, not included yet either.
And it should be noted that we have provided a lot of work ourselves, complete flat roof sealing, sheet metal work, basement sealing, parts of electrical and flooring.
The shell construction, plastering, and painting work was done by relatives, respectively uncles. We also got completely different prices here than a normal customer.
As you can see, your budget sounds like a lot, but it isn’t for a house of your size.