Power treads - Grant great attack speed and health early on.
Drum - Will provide further synergy with your move speed aura, and grants 9 all stats and 18 damage, a great item.
Nomicon 3- very similar to the play style of Rexxar, Spirit breaker can pretty much do the same thing. The nomicon minions also offer a + movespeed aura which combined with his aura and drum you will buff your teams move speed by 32%, putting everyone on your team at near max move speed.
On top of giving your team move speed, your damage combo of charge and Nether strike you can pick off any hero.
Aghanims is a great pickup since you have a surplus of intellect from the Nomicon3.