Superlative subjunctive constructions

[yevrah]

I've come across the following in a book I'm reading:

"Eran las mejores personas que podrías encontrar en el mundo."

Were I writing this sentence I would have used the imperfect subjunctive rather than the conditional:

"Eran las mejores personas que pudieses encontrar en el mundo."

Which is correct? And if both are, what are the differences in meaning?

Thanks!