Can I use a JFET like this?
This is called a common-gate configuration, it is a way to use JFET transistors for isolation and high output impedance; however because your op-amp will try to become ideal and drive the inverting input to the same voltage level as the noninverting input, would you not be able to just use a resistive divider on the inverting input? This will force your noninverting input to the same bias point, as long as you use large resistors.