The Beatles albums available as HD downloads?

As the title really, does anyone know if or when HD versions of The Beatles albums are going to be available? I’ve only got a handful of CD's (Sgt Peppers, White & Revolver) but I’d like to fill the holes in the collection, ideally on FLAC / AIF etc.

I was looking at the remastered CD’s on the official Beatles store, but not sure if that’s the best approach for sound quality given their cost?