Help with getting new ski boots

Hi,

I plan to get a new pair of boots for my trip at the end go January.
I would call myself a cautious intermediate. I am comfortable on blues and many reds and ken get down most slopes if I have to.
I am getting some instruction locally and the instructor has suggested a flex on 90.

Any advice on fitting etc. How do I know and ensure a good fit.
PS my feet are pronated - what should I be looking for to help with that.

Can anyone recommend anywhere in or near Belfast to have boots fitted?

Thanks

I have flat feet too ..have you had trouble with hire boots....find a fitter that will make you an orthotic then fit you to the boots ...I'm sure there will be someone on here soon to give you further advice...the only one to get a good review is MacSki...