Confused about virtual ground circuit
There is no need to buffer your virtual ground.  You can combine your first and second circuits by having the output of R1, R2, and C1 feed straight into the + input of the opamp in the first circuit.

I would also beef up C1. You can leave the 100 nF cap there for good high frequency impedance, but add another 10 &micro;F or so ceramic in parallel with it to reduce lower noise frequencies better.