If you had Nile's complete guitar and rig and somebody like Steve Vai to play for you it still wouldn't sound anything like Nile - and the same would be true of Nile playing through Vai's rig, he wouldn't sound anything like Vai. It's in the hands.

I know you're really after something that sounds similar and not necessarily the exact same sound and I would suggest you can get that from any of the VSTs if you know how to use them well enough, or even the amps and effects that come with any decent DAW.

Guitar on keyboard usually sounds crap no matter who's playing it - from the perspective of a guitar player; most non-players probably won't even know it isn't a real guitar but it really cheapens your track to anybody with good ears. I include all those Seaboard videos covering Hendrix and what have you, to my ears they're way below the standard of an average decent guitar player because there just isn't the range of expression available.