I think 2N7000 is a good solution, provided you keep the "switch terminals" (i.e. source and drain connections) close to ground potential. Its on-resistance is typically around 2 ohms with 5V gate drive. The reason for limiting the input voltage to 0.5V is that it has a body diode that will start to conduct at about 0.6V.
One of them acts like a SPST switch. To make an SPDT switch you will need 2 of them, and either 2 output pins (one to drive each 2N7000 gate), or 1/6 of a 74HC04 to generate an inverted signal for the second gate. To make a DPDT switch you will need 4 x 2N7000 and either 2 output pins or 1/6 x 74HC04.