As far as I can tell, there isn't anything that is directly recommended, but there are places you can look to try to find libraries that you may want to use. I would suggest starting with this [list](https://github.com/nim-lang/Nim/wiki/Curated-Packages) of curated Nim libraries, and also look into what packages were used or developed by [status](https://github.com/orgs/status-im/repositories?q=&type=all&language=nim&sort=) as they are also in the blockchain business. Here is a [link](https://github.com/status-im/nimbus-eth2/blob/stable/nimble.lock) to their `nimble.lock` file for their main crypto client.
I hope any of this helps.
