Cheers @hoops, I think that Enve might be a bit too spaceship for me!
Matthew's confirmed we're looking for a 10 degree stem... or 12 if we change the tt angle. Which is a shame because I liked the look of the frame as is it was on the computer, but it gets rid of quite a few decent stem options.
Enve aero stem has adjstable reach & angle, and is quite slender.