I've used the MAX881 for some lower power GaAs, but it's limited to a few mA gate current. TI has an opamp I used that can drive capacitive loads with +/- 30 m

I've used the MAX881 for some lower power GaAs, but it's limited to a few mA gate current. TI has an opamp I used that can drive capacitive loads with +/- 30 mA, so it makes a good gate driver, whilst allowing a decent amount of gate bypass capacitance. For temp comp I have found once you get the temp vs IDS curve, it's identical for devices within a lot, and only need to offset for pinchoff, which varies device to device within the same lot.