In reply to cfer:
Try to stick in budget, but go for best fit. Feet are important to your trip so bad fitting boots will give you a bad trek.
£150 is plenty for a good boot suitable for you treks, and there are many to choose from, you don't have to have full leather, but you do need a supportive boot,
Hopefully you have a good shop nearby where you can get fitted and get advice. They should measure your feet. And know where EBC is and what to expect
HTH