I've used both Peacock and Peebles. While Cosmological Physics is a good book on Cosmology, the sections on GR and QFT aren't all that great and you'd be best to look elsewhere. They have a serious 'skimmed over' feel to them. I'd say Peebles is the stronger of the two.
I've heard good things about volume 3 of Padnamabhan's 'Theoretical Astrophysics', but not personally got around to reading it.