I stumbled onto a link to the Website, AMPLESOUND Where I discovered Virtual Basses and Guitars as well as other instruments.
 
There are two Free downloads available that I just love.

•   First is the Ample Guitar M Lite II, which is a Virtual Acoustic Guitar. View more information  ~~> Here
•   Second is the Ample Bass P Lite II Which is a Virtual P Bass Guitar.  View more information  ~~~> Here
•  There is also some sort of Ample Percussion Cloud Drum, but it's doesn't suit me.  View more information  ~~~>  Here
• Their selection of Basses and guitars are incredible.  Going to buy the Ample Bass Yinyang II, which is the Fedora that Victor Wooten uses when playing bass.  Take a Listen ~~~>  Here

 
Tell me what you think
 

They are very good. The riffer feature is a very good addition, but you really need to be able to think like a bass player or guitarist if you are creating your own riffs. String selection is a bit alien to keyboard players 😊

 
Yep, they've been around for a while and commented on here several times most recently HERE (3rd post).  Very useable!
 

Glyn,
 
I am a Bass Player, been playing for a bout 13 years now.  I stink, but I can still read an play at the same time.  LOL   .   I dabble in Keyboards as a second instrument, but I love the bass primarily.

The sound quality of the Amplesound guitars, and the articulations available IMO is second to none.
 
I heard a demo of the acoustic version of Hotel California, complete with solo, with 3 of these playing and it blew me away.
 
Getting anything near to that realism however takes a LOT of learning and patience... like hours of tweaking until you get exactly the sound you want. So be prepared to be disappointed if you don't get immediate results.
 
I actually find it quicker to just play it for real, and accept that my old Crafter acoustic isn't a Taylor or a Martin.
 
What I would say though is if you record a real guitar first, it's much easier to "copy" that performance in Amplesound, simply because you've got all the nuances there to reference. This still takes a long time, but it's a lot easier to imitate an existing part than trying to come up with a realistic part from scratch.
 

There’s a $40-ish Yin Yang sale running at AudioPluginDeals until tomorrow.

+1 for the free Ample acoustic guitar and the P-bass.  Not to be missed!  The Martin acoustic guitar comes with an included strummer module.
 
The free P-bass does not include the bass riffer module, but it still sounds great, just like a fingered Fender P-bass! 
 
I bought the Ample Metal Ray 5, modeled on the Stingray 5 with picked articulation samples, and the included bass riffer is a lot of fun!  You can output MIDI from the riffer, so you can route the riffs to the P-bass, or any other MIDI instrument in your DAW.

I really like the Ample Sound products.  I have 5 of their guitars, the Yin-Yang bass as well as the jazz bass. All sound great and you can control them easily with keyswitches.  I highly recommend them!

Thanks for the information everyone.
 
I will dig deeper into the basses.

abacab
I bought the Ample Metal Ray 5, modeled on the Stingray 5 with picked articulation samples, and the included bass riffer is a lot of fun!  You can output MIDI from the riffer, so you can route the riffs to the P-bass, or any other MIDI instrument in your DAW.

One caveat if you are using the MIDI with a bass from a different manufacture is that key-switches and articulations will not match so the riffs may sound quite different. Some editing of the MIDI may be required to get satisfactory results. Some, like Orange Tree's Rick Bass allows one to reassign key switches so it could be possible to come up with some sort of compatibility.
 
 
I am not too keen on the effects and amp on the Metal Ray 5, the distortion in particular is too fizzy for my ears. Try making sure all the effects are off and then put it through Amplitube's Ampeg sims. Its marvelous!