The only thing to bear in mind is the extra mount/adjustment * on the treble side of the pickup. Usually pickups come with two mount screws, where as Vigier uses three (at least on the Excalibur custom guitars). I don't know if it's the same deal for the EMGs...
I change pick ups all the time on my guitars after I got endorsed by DiMarzio (trying out what I like the most), and there's no problem what so ever. I only have to order the pickup with three adjustment screws and and one extra whole drilled.I know DiMarzio does that for all customers for a small extra fee.
One really good thing that I loved when changing pickups is the fact that the pickguard can be removed from the guitar without removing all the switches and knobs. The cables leading to the output of the guitar can be disconnected. You simply loosen the screws on your pickup, disconnect the cable and you can put your actual guitar aside while changing pickups (just haveing the pickguard in front of you).
Small things like that makes me love Vigier guitars even more!! Still as happy to be on the team!!