My personal Experiance. dont use a "sign guy". I made that mistake last december and it still hurts to look at my roof. AND!! that was using my wife co worker(she works are a print shop that has a signage dept.) who was more than "qualified" needless to say i need to redo my roof and trim.
Since that probibly wont help you, I can offer some assistance, My brother and i may be able to do it for you. He used to own a small vinyl sticker buisness that evolved into wraps and then sold the buisness. Neither of us are professional vinyl people but we know what we are doing and I care about the outcome.
The place off Lee rd in chantilly is supposed to be pretty good aswell. I heard they are a little pricey but i have seen a few matte wraps that they have done and they came out good.
Just make sure who ever does it understands that there is a sharkfin on your roof that needs to be removed to be wraped correctly and to wrap the roof correctly