If it was me, I'd simply try a new cheap stem with your current spacer situation and see how it works. You have a pretty good idea about what you want to accomplish. You realize that the stem calculator for angle and length that you've used probably won't hit your fit/comfort need exactly. So, why not just get a stem that you think will accomplish it? Like, same or similar angle but 5mm shorter or longer if you can find it? I'd do it while keeping the spacers below the stem, but that's my sense of aesthetics.

PS: I have used that stem calculator and found it a great way to visualize and approximate what I was trying to accomplish. But in the end, I just had to find a commonly available stem that got me close, but not exact.

I have also used the Specialized stem that can adjust angles with shims in the steer tube clamp hole. That opens up some subtle tweaking.