Coffeemaker couldn't care less for pure sine, unless you have one with digital pad.
Bare in mind that bigger inverts have bigger fans, that not only make bigger noise, but also draw bigger power.
I found that for small stuff like laptop, or cellphone charging the 100W inverter is the best. Those are very compact, no fan and I bought one for $8 on sale. You just plug it into 12V socket inside the camper, so no hassle with wiring.
Than when you need big guns, the 1500w or more would be probably more recommended as you could hook up microwave to it. With this one you have to worry about big cables, proper cooling and remote.
Although I install my 1750W inverter under kitchen sink and can reach the switch on its panel by opening the cabinet. It come with remote, so used it after-all just above duplex extension at the countertop. I also installed switchable 150 amp breaker on big cable, so I can completely disconnect it when is storage.
