In addition to the above gear suggestions (where I agree with most except for weapons, waste of plat compared to instruments and armour), I'd like to recommend Barbed Ringmail Gloves (from Velketor's). I picked up a pair for 1K and they're hard to beat for non-ToV gear.
For shoulder slot, my permanent choice is Imbued Granite Spaulders (from Hole), it's difficult to argue with anything but the weight, wimpy Bards that we are
[You must be logged in to view images. Log in or Register.]
As for doing stand-in tanking duty, sure it's not ideal but neither is it an awful choice, given reasonable gear for the job. Bards sport much more defensive cap than offensive, and songs have plenty of potential for pissing off NPCs, at no mana cost.
Finaly, wee little note about Bards and weapons post 20ish level; Really not where I'd put any plat investment, a few utility procs like Orb of Tishan is all I'd consider putting in my main hand. Often consider using a shield in offhand, certainly would if I had a good one with epic and/or beast drums and other main hand useable instruments. I do not nor do I see it happening so I stick with instruments 90% of the time.