Since it's not easy to answer to your question in short version, I would say, it depends...
There are many different Korean words that can replace "would be" but again it's all depending on the sentences.
From your example above, "would be" is "될 것이다" in Korean.
If you say - It would be nice if blah blah blah...
Because of "if", "would be" is "텐데" in this sentence.