DVD media compatibility

[Pugwash]

Hi, I'm currently knocking up details of a wedding-video-to-dvd service I'm starting locally, but I'm not sure of DVD-R/+R media and how compatible they are.
Is there a reliable tested free list of brands and dvd players I can use on my own site, or should I point visitors at the 'geeky' dvdrhelp.com site to find out if -R or +R media works for them?

[datsun1200]

more dvd player play dvd-r . old dvd player will not play dvd+r a lot of new player will