Bloodshot Reborn (Lemire's series) doesn't require a whole lot of background knowledge. I would only recommend reading The Valiant beforehand. The Swierczynski Bloodshot series is very much a 80s/90s action movie. The story is good enough to keep you there, but there's not much substance to it.

Yes, Scribd has all Valiant titles released up until 6 months ago, I believe.