"looking for make , model, unit & quantity if possible.
want to be accurate.
doing this for a friend."
What you're asking is some serious scholarship Panzerjager -- that's why you've rec'd some dismissive replies.
Like someone else said, you're looking for unit dispositions on the eve of Citadel. May I suggest the french language book "La Bataille de Koursk" by Francois de Lannoy, published by Editions Heimdal. He has org charts and broad categories of AFV types (# of tanks, # of Stug) for Heer. Nothing on Red Army dispositions.
There are the two volumes "German Orders of Battle" by George Nafziger.
Try to get them through inter library loan.
Get some books related to the subject and scour their references. And then scour them. You're nice to do this for your friend -- but if he/she is serious about being a history author.... well there's sweat involved.