I have the same old problems with trying to find a boot that fits. I have wider feet with a skinny ankle and high instep. I have bought a number of boots over the years but none really seem to deal with all 3 problems. I have bought from shops in Japan, Canada, Australia and Europe and even though I have figured out what I need I can't seem to find the right boot for me. I still ride park most days in resort unless the snow is good. At 65kg a 100 flex boot would be perfect, but any boot that will fit my feet and ankles would be nice and I can tinker from there.
Boots I've tried:
Salomon SPK 100 - didn't fit my foot at all. No room over the instep so I took most of the rubber boot board out and cut the liner out to make space but no room for footbeds. I put 2 sets of ankle wraps in to try and hold my foot down which helped a little but took a lot of trimming to stop my feet cramping. Also no cuff adjustment was a little annoying as my knees tend inwards but not a major issue. The boot flex was perfect for me and was perhaps the only thing apart from money that kept me in these boots for the season.
Atomic Tracker 110 - slightly narrow and had to be punched out especially around the toes. Cuff adjustment and room over the arch made these the best fitting boots for my feet that I have tried. That said, I still had a lot of room around the ankle and especially my shin even when the boot was fully tightened. Also I think a mix of the 4 buckle system and a little extra flex gave me very bad shin bang after a few hours, to the point where I would need a day of snow after 2 days of riding just to let my shins recover.
Dalbello Krypton Pro - These came with two tongues and I used the softer one which was meant to be 100 flex but was definitely softer than the SPK. These didn't have enough room over the arch but fit the width of my feet well. I had too much space at my ankles and again the boots gave me terrible shin bang.
I've had a few other all mountin boots before then but I don't remember the models just that I have the same issues and it seems like every time I go into a shop I have to choose a compromise.
I have also tried on a lot of boots in shops. I have found a compromise of a narrow boot with a high instep and just punching it out and dealing with the shin bang. If anyone has any boot suggestions or what the best approach might be to finding a solution I would really appreciate it.