Try this web site for clips http://www.wesales.com/ the clip # is 178 and it is a perfect fit.If they don't sell direct they should be able to give you a distributor in your local area. I hope this helps.
Iv'e been to quite a few websites looking for rocker panel mouldings and I remember they all stated you had to use your old clips. Then I read somewhere else that the repro chrome rockers dont align with the holes correctly. Someone sells some sort of adjustment attachments for this problem but, I can't remember for the life of me.
I got repro rocker chrome and the clips from Muscle Cars Only. I had to do some work on the clips to make them work without damaging the chrome. Basically I had to compress the piece of metal (on the back of the clip) that presses against the chrome and keeps it from sliding out of the edges. Without doing that it would dent the chrome. Then I used some silicone to secure the clip in place and keep it from falling off.
I also had to compress the part of the clip that goes in the hole and use silicone again to keep it from rattling around.