I'm considering getting a Windows Surface Pro from marketplace (not sure of the version number yet, I'm waiting for a response.) Do you know if Ink/stitch works on this? 

I'm not seeing any open bugs reported specifically related to Inkstitch and WIndows, or Surface pro. https://gitlab.com/inkscape/inbox/-/issues/?sort=created_date&state=closed&search=inkstitch&label_name%5B%5D=OS%3A%3AWindows&first_page_size=20

Nor any open bugs related to Surface (OS Windows): https://gitlab.com/inkscape/inbox/-/issues/?sort=created_date&state=closed&label_name%5B%5D=OS%3A%3AWindows&search=surface&first_page_size=20

Others may have direct experience and can chime in.

So, yes? Ink Stitch DOES work on a Surface Pro?

I can only say I'm not seeing bug reports. I'd ask on the chat to see if there are any anecdotal comments regarding the Surface. https://chat.inkscape.org/channel/inkscape_user

Might be able to get an answer here: https://www.reddit.com/r/Inkstitch/

Do you know the version number already?

Is it a arm or intel processor?