The Hunt For Big Fish with Larry Dahlberg

I'm designer a new fly to put on the market, its being made to target amazon Peacocks. It will be a sub surface fly in the tradtion of flies suck as Nick Granato's chupacobra(sp). I'm trying to think about what would fishing for these fish require in a fly. Beside alot of color patterns, i'm wondering what would you like in a fly for these fish, how bit, how castable, what kind of profile? You want it to push alot of water or be gentel on the strip? How big?
Let me know what i should be tying here.

Thanks!

First I'd like to say, it's a stretch to design a fly in "one shot" for a fish you're not actually fishing for! That being said, it depends on what you are targeting. If you are trying to catch a legit big one (high teens into the 20# range) usually size, commotion and speed are the keys.
For smaller fish, it's just gotta seem like it's alive and wanting to escape. I've had best success with brighter colors, esp chartreuse.
best
L