How to find a consultant to help me with a Storyline project

Here's what I want to create for a psychology research project to demonstrate how attentional focus on anxious thoughts narrows one's field of vision by allowing the student/user to take the perspective of a subject viewing her environment while her thoughts change. 

A video will be  running full screen as the base layer. The video represents the subject's view of her surroundings. 

A circular aperture can open and close over the video layer.  The size of this aperture can be adjusted from wide open (full screen) all the way down to a small circular field of vision in the middle of the screen.

It would be even better if the transparency of the aperture could also be adjustable.  

Over the video and aperture are two independently scrolling layers of text. These represent thoughts going through the mind of the person viewing the video. 

The size and transparency of the various words or phrases in the text (“thoughts”) can vary according to how much attention the  subject is giving to the thoughts.  

Overall:  I need to be able to coordinate the size of the aperture to the degree of attention particular thoughts receive. 

The degree of attention they are receiving is represented by the size and transparency of the thoughts. 

 It will be as if the user is viewing a changing environment through the eyes of a subject whose field of vision widens and narrows according to the size and transparency of the “thoughts” in the scrolling text. 

This will all be coordinated with an audio track explaining what is happening. 

Our current budget probably will not allow hiring someone to build this complex scene, so I am seeking a consultant to tell me the best way to do it, i.e., what should be in layers, what should be in states,  what would be the best triggers, how I can vary the size and transparency of the scrolling text, and how I can vary the size/transparency of the aperture.  All of this, of course, on top of a running video. 

So my question is:  How do I find a consultant who might provide a bid?

Many thanks for any and all tips!

Pablo Miller