Inverter capacity?

I try not to ask questions which have been repeatedly discussed but sometimes the right answer is hard to find with the search function.....

I am thinking of installing an inverter but am not sure of what size I will likely need to accomplish what I was wanting to do. All I would want it for is to possibly run the microwave for a few minutes if needed, the coffee maker in the morning, and the TV for 2-3 hours at most. Obviously not all at the same time though..... So with that said, what do you guys think? And I've also heard that pure sin wave inverters are the only ones to get.