wow, busy weekend in
Birmingham...busier here in the office
back to the OP get your feet measured and then try the shell on the foot often times you will need to go to the size below what you measure, ski boot designers used to all use monopoint sizing so a boot for a size 27.5 foot would be 29cm internally leaving 1.5cm for the lienr and toe room...now they are all over the place measuring from 28.5 to 31cm internally for the size 27.5 this is why the only way to tell the correct size is to carry out a shell check
as for buying boots online well i am dead against it [some might say that's because i sell and fit boots but i have seen too many people who bought the colour they liked in the size they thought was correct only to find out that they were chucking money away
the only things that determine what bootsyou should get are the shape of your feet and your skier level, if it means not going to the pub next saturday night so you can afford to have the best for your feet buy a six pack and watch a movie