This Pet Goldfish site where our forum is you can find some info: Articles > Type of Goldfish > Celestial Goldfish.
Care level Medium, because of their poor eyesight, the eyes being on the top.

Shubunkins would be nice with Sunshine, or a deep red Comet

Andrea,
Most slow moving celestials and bubble eyes do not have a dorsal fin and therefore would navigate very slowly around an aquarium and have extreme trouble finding their food because of hindered eyesight.  They are also not the easiest keeper of the goldfish world. Because of their large bubbles, bubble eyes can injure them quite easily.  The bubbles can grow back but it does risk infection or fungus. You cannot have a powerfilter with bubble eyes or any ornaments in your aquarium.  Even gravel would be a no-no since they rest on the bottom of the aquarium quite a bit.  Their bubbles around their eyes are delicate and heavy!!  Some get so big that they cannot get off the bottom of the tank and feeding them can become quite a challenge.  I would stick to a slim bodied fish or maybe if you have you heart set on an egg bodied shape then get a pretty fantail who can easily go after the food competively with your comet.
Incidently you should know that ALL breeds and varieties of goldfish will interbreed with each other. They are all from the same species, Carassius auratus.  All those exotic looking goldfish came from this first drabe olive colored wild carp!  So getting a celestial or bubble eye would not prevent spawning or babies from accidental breeding.
There are over 100 varieties of goldfish!  What we see in the petshops to buy is a very small example of all the different breeds!   

Yeah but aren't puffers marine/saltwater fish?

Thankyou so much Mindemae. That's exactly what I wanted to know. So it looks like for now celestials and bubble eyes are a no-no. Maybe one day I'll get a special tank for them and have a black moor and pearlscale in there too

I actually started researching them on the internet yesterday and read all these horror stories about their eyes popping out!! How horrible

But omg! I never knew that about goldfish, I thought they'd only mate with the same type of goldfish. How silly of me seeing as different breeds of dogs, cats etc. can mate.

Maybe I will just get another comet seeing as I do love comets. I'll just search for a different colour one to sunshine. Or stick with the shubunkin. I don't mind in the end and I have a few months to decide

Thanks for all the advice once again.

Kat: I love puffer fish too! They are so **** cute, I just wanna hug one Though I don't think that would be a good idea and I'm not experience enough to have a saltwater tank yet.

We saw these adorable little orandas in a pet shop not too long ago and thought about a second tank for them, as they'd probably get outswum by our shubunkins and comets.
Sometimes the right goldfish is worth the wait.  We ordered ours, but they didn't come in, so the manager at the store said we should get another type of fish instead.  We choose to wait and see what else came in, and we're glad we did!  Now we wouldn't give up our current fish for any others.  The moral of this story?  The right fishy friend is worth taking time to find.

Nicole: What type of goldfish did you have to order? I'm thinking of ordering a comet which isn't orange as all the ones at the fish shop are orange and Sunshine is orange so if I get a comet it would be nice to have a different coloured one

I'd said he is more a pale orange bronzy golden but I would like something quite different. An extreme orange one would be nice or any of the ones you mentioned, cream would be good