The sword and breastplate Ari can tell you enough about to fully identify: the Sword is a Holy Avenger called the Purifying Radiance and the armor is +2 and Soulfire. They have been in the service of Stasis church for centuries.
Of the rest only two can you identify: the Belt is a Monk's Belt. It bears the mark of the Shrine of Korda. The horn is a Horn of the Armus. It bears the same mark. It is very powerful, made of a doggeden horn and bound in iron.