Switch at output of operational amplifier
The Analog Devices ADG812YRUZ has 4 SPST switches, 0.65 ohm typical on resistance, and comes in a 16-pin TSSOP package.   It switches in &lt; 30 ns, has a THD of 0.02%, and a -3 dB bandwidth of 90 MHz.  However it can handle only 300 mA continuous.  (I assume you could parallel them for higher current.)