Time to start recording your very own library! It's easy! Get the best players with the best instruments into your favorite studio. Make it future proof by recording every microphone possible. Make sure that each note has commitment and real feel. Especially the "ppp" ones, which are hard to do with conviction, add vibrato and dynamics, figure out legato - and voila! A few million (!) dollars poorer you have the beginnings of something's acceptable...oh, and con Sordino can Not really be faked up. So that bringing them all back in for a week. Short notes? At least 8 dynamics (we are now at 64 - but we are mad) and staccatisimo to quaver, crouched,minim, semibreve marcato -at least eight velocities and 8 round robins.
Pizz, Col leg, sul tasto, sul pont... I started this in 1994. We are still at it. It getting somewhere, and sometimes I like it... it's lots and lots of work to do for the four full time employees in the sample department...
So, roll up your sleeve and get Exactly what you're after!
But perfect is boring....