I'd recommend Nic Nowego which is a modern Irish pub (it's at Św. Krzyża 15 street).
Good call and while you are there ask Tom for a Davidek drink ;)
You most likely won't be dancing there, but the rest what you're seeking is there.
Have you never been on the bar dancing to Gary Glitters "my gang" ? :D
You could also pop into the Irish Arms bar, they have live gigs on during the weekend. Maurice is an auld fart too ;)