If you're willing to send you slide only, there is a member here who has offered to install sights for members at no cost. Member pays shipping of coarse. You may recognize the members name if you've used the archives as he has written a number of threads about different trigger systems, parts required, etc. He goes by "twosixty". You can send him a message through his profile page
View Profile: TooSixy - HKPRO Forums
Unfortunately, he is currently serving an administrative ban for whatever reason. That may or may not effect his generous offer and he may have an issue with using the PM function.