Ta'varis will ask for just regular Splintmail heavy armor as opposed to Masterwork. If the damage reduction isnt going to stack then it is silly to waste the gold.  

He will ask around to see if anyone has these 2 items for sale. 

1] Pearl of Power [uncommon] - DMG p. 184

2] Periat of Wound Closure [Uncommon] - DMG  p.184