2 Parts: Best clam chowder in SF? Best Irish pub in SF?

I’m planning a birthday evening, and birthday boy requested clam chowder (the creamy, New England type) and also an Irish pub, with a 5–8 person group of friends. So I’m looking for recommendations for both, which could be totally separate, nearby each other, or who knows, maybe even the same place!

High points: inexpensive but decent food/beer, good atmosphere and comfy for talking and hanging out a while. The more Irish flair and personality the better.