Mirror Carp and Carp both have those deep fat bodies, thats the kind of structure I meant.
Ghost koi are extremely common in Europe, beautiful and not too expensive.
The japanese do not consider them to be Nishikigoi (koi) they are considered to be a hybrid and therefore undesirable.
Personally I may be Biased but they can be extremely beautiful fish.
Butterfly koi are in a similar standing with the japanese as they were bred to a population of carp in indonesia that were discovered with long flowing fins. The gene is dominant and thats why it was so easy to create butterflies of more or less any Koi.
I have not kept koi in quite a while but I will always remember one thing that stands out as quality.
The cheaper koi are farmed in Israel and have been produced there for a long time now, in general the higher quality japanese koi tend to have rounder faces. The lower quality individuals with more pointed snouts would not usually be supplied from Japan.
Essentially some traits that would be worthy to cull in Japan are not the same traits used for cull selection in Israel.
Things may be different now, unfortunately I only ever kept koi in Europe. I have no experience with the NA koi scene. Here its too cold to keep fish outdoors all year so I'm unsure if I will get to keep them again unfortunately
As with anything its personal preference, I don't think your fish look all that bad and as long as you are happy with them thats what really matters