Beginner stocking in a newly cycled tank

[Helms Reef]

I have 2 clowns. Pretty small ones. Any thoughts on what to add next? Eventually I want a yellow eye Kole. What would play nice with the small clowns. 55G Display FYI and sand substrate.

 

[ReefRusty]

This is always good to look at to give you an idea.

 

[Helms Reef]

I decided on getting a long nose hawk fish and a tomini or Kole. Would it be best to introduce these at the same time?