PBN Domain extensions

I want to buy some expired domains for my PBN, do it's necessary to use ".com" as the domain extension, or using other extensions like ".net" ".us" or other domain extensions will be fine?

Thanks!

Basically everything is fine. I would stay away from .cc / .info and other extensions that was used way too much for spam in the past, but apart of that - everything is good.

Think about any normal website - do they have links only from .com domains? Why you would have such obvious footprint..