Help with PRG 5100's. Stock Springs?

I had posted these for trade but my buddy was able to dumpster diver and get my stock 09 pro 4 springs back. The eibach 600's are a bit stiffer in the dirt than I want so my questions is what do I need to get the stock springs on the 5100's from PRG. I just need the lower spring seat as I think PRG uses a custom one for the Eibach's. Is that correct?
As for the upper mount should I use the PRG billet one that's one there now or my stock ones?

Thx guys