First check the input watts on its label on the back needed to run the microwave. EG a "1000w" MW might want 1500w input. The PSW 1500w inverter would be maxed out. Might get away with a "900w" MW.
With a B you will have limited room or weight for a the usual four batteries needed to run microwave type high amp drawing loads. However, AGM batteries are much better at this, so if you can only carry two batteries, have AGMs for that job.
Next, question whether you really want/need an inverter/charger which is expensive, when all you need is the inverter. The B will already have a converter.
You could use the money saved there to buy the AGMs.
There are several wiring options for inverters that have their own receptacles but limited options for hard wired ones.