Window regulators: I have narrowed down to a small group of vendors who I believe provide good quality parts. However, the warrantee on these parts, (particularly cable regulators), is generally 30 days. You can choose to go with a dealer part but be aware that the part may cost up to four times as much as an aftermarket part. What I will do on all motor/regulator installations is give you a 3 month labor warrantee and whatever the manufacturers warrantee is on the part(s). (generally 30 days) The idea being, if something should go wrong with the part(s) in a 3 month span, the labor would be free. I believe this is a fair way of handling it. 

All other parts: manufacturers warrantee