I have the same problem, and use a boot with an ankle strap . Mine's a very old airwalk boot, so probably can't buy them anymore, but should be other brands available I guess.
http://thirtytwo.com/ they do boots with moldable liners. I haven't tried them, but heard they are pretty good.
I would go to a snowboard/skate shop in Zuerich where they know how to find the right fit for you, and then rent the boot so you can try it out before you buy...
I wanted to hire multiple pairs of boots while I was away, but they were all the same brand "Burton".
They were lace up jobs, and although they did bruise my calf muscles, I experienced NO heel lift in them at all.
My riding was infinitely better (despite the bruising), and have since been handed a similar old pair of boots from a friend here in Zurich (worn once).
I'll try these new boots out on the weekend, and if it's all good....... problem solved.
(Ditch the Salomons - Clearly not a Brand or Quality issue, just a "Fit" issue)
Thanks for everyones input all the same - greatly appreciated.