AS you are finding there is very little out there as 55cm is becoming a size of the past. From that list which is as complete as I can think of.
Stoves, Belling and new World are all the same group, Stoves used to be very superior in quality but in recent years this has decreased as price erosion has taken hold, Belling is next best with New World at the bottom of the pile.
Amica is a small budget European brand with not a lot of back up here in the UK.
Which leaves Zanussi which in my opinion is the best of the bunch. John Lewis is the best place for these as they also offer a two year warranty.