You should be able to get up most UK hills with 39-23. I would swap the chainring first.
Thanks for that hamster.. I went up a hill yesterday with a 16% gradient and that was tough.. Nearly stalled it .. There was a warning sign at the bottom and I pulled the toestrap that tight that I broke it.... Got a cable tie off a lad in a van and then couldnt get a pair of snips to get out of it afterwards... A good days craic....!
You can Never have too many Peugeot Bikes in One House !