Head Stratos 27.5 is plenty of stiff and the liner is not shortened in the boot. Regardless of brand try to get a .5 sized boot in SB HB's as they liners and shell are the same size. If you had a problem with your toes in the liner of the Ingemars, and not the plastic it should work. The liner of the Stratos is fantastic and didn't even need to be heated for me to fit. They are really snug when I put them on, but after a day riding I forget to unbuckle them.
The only thing that kind of puzzles me that you say you have narrow feet, because Heads are regarded as the most wide boots, together with UPZ's. So Ingemars should have been giving problems as well.
Why no asymmetricals? I think the Deeluxe 700 is a really good boot apart from the horrible fit (for me at least). Topsurf sells them, maybe close to you too:
http://www.topsurfvinkeveen.nl/component/option,com_virtuemart/page,shop.browse/category_id,156/Itemid,37/