Bigger isn't always better, especially when it comes to a/c units. the worst thing you can have is one too big (no idea if what you are looking for is too big). You'll be cold but clammy. Under ideal conditions, the a/c runs all the time and keeps the house perfect temp...you get maximum benefit of dehumidifiaction (which only happens when the a/c is actually cooling). Otherwise, you get a cold blast, it shuts off without passing the air over the evaporator (to wring the moisture out and cool) enough and dry the air. It may be that some rework of the air distribution is what is really needed, not a bigger unit. You won't know without a proper heat loss calculation.