Are the bars in your illustration the same profile as the ones you intend on using?

If so moving to a shallow compact bar such as an Ergonova would allow you to run a much lower stem whilst maintaining the same hood position.

I've just gone the other way- switching from Ergonova to Rotundo to get around an inch lower (didn't want to change the stem).

Evening All - Many thanks for the feedback and help. Going to go with the +10 deg. stem and spacers for now. I'll play with exact position/setup when all built up, cut steerer when certain later.

em3 - thanks for the link that's already where I've been playing with the numbers from the fitting and the stem arrangement discussed here. As they say, great minds think alike.

Dammit - Bars were just for illustration. I'll be putting my Ergonova Team bars on the build, love 'em.

Looked at the next stock frame up with the builder and it didn't really work for me against my measurements plus, I wanted to run a layback post rather than longer TT as historically it's worked better for my dodgy knees. Flexibility wise - When stood up can put my hands flat on the floor and touch my knees with my forehead so guessing that gives me some room to play with the postion a bit when all's assembled.

It'll be another week or so until frame arrives and then I'll post some build pics. Cheers!