one thing almost all replicas have in common is that they don't fit as well as authentic bodykits...so your body shop(unless you have a lot of experience, body kits should be done professionally) will have a more difficult time doing the install.
this really doesnt affect you financially though, because price of install will be basically the same (if they want to charge more--find someone else).
but it may affect your car looks-wise. many replicas will have small gaps in the sideskirts and a close friend of mind actually had to shave some of the side of his replica front bumper off to make it fit.
also, a couple of people here on ecelica have said the stock fogs don't fit on their replica veilside kit...so you will probably have to go without fogs. (on the authentic veilside, your fogs are not a problem to installation)
you might want to pm romkapomka (sp?)...he has a replica veilside. send romkapomka a PM