Here's a thought. You could use basic martial attacks, but encourage characters to pick up stools, mugs, push people, etc. Whenever they do so, hand them a couple of power cards that apply to that particular weapon. For instance, you pick up a mug, you get the following:
EPIC MUG
This pewter tankard has seen its share of epic barfights, judging by the dried blood that has never quite washed off the bottom.
At Will - Mug Smash - Wielder makes a melee or ranged basic attack, dealing damage as appropriate (all nonlethal). The mug adds 1d6 damage to this attack. If used for a ranged basic attack, the mug must be collected again to regain the use of its powers.
At Will - Swill - Take a long drink from the mug, granting the wielder a healing surge. This may be used 3 times before it is expended. When the mug is empty, neither Swill nor Throw Contents may be used.
Per Mug - Throw Contents - Close blast 3 - Attacks Reflex; Targets are blinded, save ends. This attack empties the mug; afterwards, neither Swill nor Throw Contents may be used.
You could make different little powers per item, and let players be creative and come up with their own uses. It could be fun to have some special bottles behind the bar, perhaps some exotic fey wines that have really strange powers. And certainly, one or two of the patrons ought to be an elite badass of a brawler.