I'd go with Luca. Here's why:
I was assigned a feminine name at birth. I shortened it to a male-sounding neutral-spelled name (ugh I'd totally tell you but this is the inter webs and no

)
For the first couple weeks I used my new name, it felt awkward and forced and just altogether uncomfortable when people said it. By the end of month two, it was less awkward. By the end of month three, it was officially the best decision I'd ever made.
I went somewhere the other day, and, upon realizing that I was dfab, the front desk lady said, "Oh, well, what's your
given name? This must be shortened." (I recently legally changed it to my new name) - people might ask this question. Then they move on, accepting that
okay, your parents are a little weird for naming you that and, hey, who cares about a name, right? If you choose Luca, this is slightly likely to happen when you're presenting as either gender. When you choose Lucas, this is extensively likely to happen until people can automatically grasp the fact that you're a guy. Thing is, the people who notice "Lucas" pre-transition are going to do more intense eyebrow-raising than the people who see you as "Luca" in whatever gender. The people who are raising eyebrows at "Luca" are probably not going to have strong feelings about it because it's a
lot more neutral, and exactly like you said, it's often a male name in other countries. You have an easy out of "oh, it's a [m/f] name in [x country]" if you need that option.
In terms of naming yourself, no one would ever name their child North West. Well, look, someone did. You just have some uber cool parents who happened to like a foreign name.
Make sure your entire name sounds good. If you don't like the way Lucas sounds with your surname, that's a huge thing.
Remember, too, you can always have middle a middle name that goes with one or the other. So if you're going with Luca, and you want it to be more masculine, add a "Bryce" or a "Liam" or a "Felix" in there to put on documents or in email signatures or letters.
Good luck with everything! Hope you find a name that's right.