I'm in search for spacey guitar sound as much as heard when using pedals such as Eventide Pitchfactor and Modfactor. I believe there should be a few plugins which can do the same trick (mostly by similar architecture and good presets). Any recommendations ? Using chains of chorus/delays/reverbs doesn't do the trick so well. I believe the pitchfactor is something which is unique so I'm in look for a similar plugin... Thanks !

Try the ValhallaDSP plugins. Shimmer and Übermod could work for you, I'm not 100% sure as I haven't used eventide effects.

(edit) Sorry! You asked for free plugs. I don't know then, but Valhalla plugs aren't expensive, so try the demos if you want