You can get the DG(s), just wanted you to know that sometimes people have troubles with the disease, it doesn't affect other fish, as far as I know.
When you say you were really looking forward to the RL and Kuhlis, what do you mean? You can still have them?
I'm wondering, could you order some fish online? What is your LFS, a chain store or like a fish-only place?
Perhaps you could do some micro fish, such as mosquito rasbora? They're quite lovely and they stay small so you could have quite a few I'd think.
Another fish you may be interested in, though not sure if you could get a hold of, is Spotted Blue-eyes (Pseudomugil Gertrudae), they're very pretty.
If you were to do a goldfish tank, you could only have one. 30g for the firsty fancy and 15g for each additional.