Simple ESD mat and wrist wrap setup
It doesn't matter, as long as some resistance is there.

The resistor limits the current from the discharge to something that won't damage the device. The actual value of the resistor is mostly arbitrary, it should be large enough to properly limit the current from even an 1 kV difference, and small enough to eventually allow the potential to even out within a sensible timeframe.

Whether it's 500 kOhm, 1 MOhm or 2 MOhm is not that important, so use whatever is most convenient for you, ideally a configuration where the wire from the wristband doesn't catch on the soldering iron all the time.

I'm using a grounded ESD chair, which is even more convenient, but I've also seen ESD sandals and grounded floor plates.