This isn't really going to help that much, but my advice is to go to a good local store (one that specializes in skiing, not a general sports store), and just try on every boot you can find. The most important thing is to find a boot that fits you. Go for one that gives you good support (not too soft), but that you can still flex. Avoid the temptation to get it in a slightly bigger size than you need.
Don't be too worried about what category a boot fits into - if a racing-type boot fits you and it works, then go for it, and conversely, if an intermediate boot fits your foot and isn't too soft, then that's what you should get.
Personally I really like the Lange Comp series of boots - but that's just me, and chances are you'll have a different opinion.
Finally, definitely look into custom footbeds. They can make a world of difference. They'll be more comfortable and let you ski for longer without your feet getting tired, and you'll also have better transfer of the motions of your foot to the ski, so you get better control. They are somewhat pricey, but it's certainly worth it.