What DC-DC do you reccomend me to use to get the +5V needed for the amplifier?
You don't need DC/DC - maximum load current for +5V is just 4.5mA, so any linear regulator will be fine. Use one with EN signal to turn on/off +5V voltage (VG2).
Much more problem will be with VG1 (-2V). It should be adjusted in range -2V till -0.5V during startup. I think you need some DAC (it cound be real DAC or just PWM + RC filter) and invertor (on opamp) to perform this task.
what is the best wat to measure the current going threw the amplifier
You can use any current sense amplifier (from specialized IC to shunt resistor and instrumentation amplifier) and ADC