The Nexus guitars aren't appropriate for funk guitar at all, not even close. You *can* get away with using their electric bass stuff, and their muted guitars sound good, but they're typically synthy (albeit less so than most synths/romplers that try to incorporate guitar sounds).
NI Funk Guitarist is definitely a solid bet, I'm pretty sure it was used for the guitar in Moves Like Jagger...it sounds identical, but they just made a custom riff pattern for it as it's definitely not a preset pattern they're using.
I'd always recommend actually recording a guitar so that you're being original, but it's not feasible for a lot of people...learning it or booking someone, and buying recording equipment if you don't already have it. Us bedroom producers just want a VST for everything :).