There is an item limit of like 950 items or something like that. Pritty hard to legally hit the item limit.
Full backpack 125 items
Full bank box 125 items
FIVE full pack horse/llamas 125 each
Plus what you have equiped 10 plus robe, quiver/cape, talisman, one handed weapon/item plus sheild
which is still just under 900 items by my count.

When you get to your destination shard, you have one REAL week to claim your pack animals, your inventory, and your formerly equiped items. Pack animals, when loaded up can not be stabled. Sujest feeding them before you transfer though to make sure they make the trip happy and all. Drop any guild tag you have before you transfer as well and check server maintanance times on destination shard and you are all set.