Now THAT sucks - wait wait wait wait....
I just went through the same violin solo sound search myself, using Kontakt. O am working up a midi version of a Dixie Dregs tune, called Night Meets Light, and there is a TON of solo violin throughout the song, including a violin solo.
Most of my strings presets are for sections, violin section, cello section, etc..
I found a reasonable sound with the original Kontakt factory sounds library, Solo Violin, and at first was driven crazy by not having any means of controlling vibrato. Lots of other articulations with the bowing, and all of that, but not for vibrato.
THEN, I discovered that the amount of vibrato present seems to depend on the velocity of the notes - the samples loaded when a note has a velocity of 100 have far less vibrato than the samples loaded when the velocity is 115.
So, for whatever the worth, if you are having trouble with vibrato, try adjusting the velocity and see if that works the same. :)
You apparently have some time, wait wait wait wait wait.....
Bob Bone