I'm not sure moustache bars are really going to end up being more upright. Many people who are converting older bikes to moustache bars end up putting a taller stem on it to get the bars up higher. And I know on my commuter, putting moustache bars on ended up stretching me out more (to reach the brake levers in the curves), which was fine, because it was a tad bit short in the top tube for me, but I think I could still use a taller stem to get my bars more even with my saddle.

You could try flipping some moustache bars over, so they rise up slightly, instead of dip down. Or, if you can find a way to make the STI levers work with albatross bars, that might be a better bet. (Or talk him into bar end shifters on albatross bars, which would probably be your best bet.)