I don't know if there's a discord channel, maybe there is but I've got no information about that. This question can simply search the answer through Google.

These are the two websites that popped up after asking the keywords that you're looking.

https://www.advfn.com/cryptocurrency/coins/mineable

https://www.coinlore.com/mineable-coins

And about the "upcoming" coin details, I think the best idea is to check the newly listed coins on coinmarketcap and coingecko and check if they're PoW.