Whiteline poly bushings are working fine for me ... though in hindsight I wish I had gone with solid bushings.
Why are you replacing your subframe?
If your diff bushing is shot, there's no need to touch the subframe - it's just a way for the dealer to line their pockets by unnecessarily charging you for a $900 part and $1600 in labor for something that shouldn't cost you more than $300-400 total.