The Helm of Balduran is in the Irenicus dungeon in a trapped cabinet.
To my knowledge the Cloak of Balduran doesn't come over, though I could be wrong.
Deirdre in the Adventurers Mart has the Sword of Balduran, the Shield of Balduran, and the Plate of Balduran - but no cloak.
Details on the items can be found here in the equipment section.
The only way to get the cloak I can think of is to use Shadow Keeper or the CLUAConsole.
P.ath o.f M.ost R.esistance
- No matter how subtle the wizard, a knife between the shoulder blades will seriously cramp his style. (Vlad Taltos - in the book Jhereg by Steven Brust)