Definitely bring the drytop.
If you're looking to lighten your load a bit, you can probably skip the splashtop. The water here is cold enough in June that, even if it's a 95 degree day, all you have to do to cool down is roll a few times.
A drysuit probably isn't necessary--if you never swim. But, without a drysuit, you wouldn't want to be in the water more than a couple of minutes.