I'm not sure if you have gotten your answers for this yet, but I have an idea that might help.
I am planning on doing the same thing and I will be using this pattern http://www.simplicity.com/p-2235-men-teen-costumes.aspx
for it. I will shorten the coat tails and sew on the ruffles by hand on the sleeves right before I attach those to the main body of the coat. It might be the easiest thing you could do. Look around though.
“Fear Has A Large Shadow, but he himself is small.” - Ruth Gendler
Cosplays for 2011
Riku Replica- Kingdom Hearts (Re: ) Chain of Memories 15% done
Len Kagamine - Story of Evil Arc - Vocaloids 0.5% done
Ciel Phantomhive - Black Butler 0% done
Autumn themed Lolita - 0% done
South Italy - Hetalia - 0% done