Probably a much better option but I've only used GW so I can only compare what I read on paper about SR. But I'm sure the Vets will have a much better answer for you.
It's perfectly fine to use sr9009 in pct, but NOT as a replacement for GW. The main reason GW is used in pct is because of its effects on lowering cortisol which causes catabolism and muscle breakdown. Sr9009 does not have this same effect