Hi there,
I use to use parts4repair.com when I can't find replacements at replacebase.uk.com . I think parts4repair holds good quality. I've bought full screen replacements for Nokia N8 and Iphone 4s and 5s. I've also bought housings for N8 and Iphone 4s. Latest I bought full housing and full screen replacement for my N9. Haven't got it yet though so cannot tell you more. However, the other screens I have bought does have had fully functioning proximity sensors and cables. Hope that helps!

/Mikael