I'll bet that Future would put a nice, high-gloss, super-smooth sheen on the top, and eliminate the orange peel, although I've never used it, but plenty of guys here swear by it.
I understand about the base now...good call on using a display case! A perfect way to display it!
That looks Like a light rain just starting to fall in the photo...I don't think you could simulate that with Future; from what i understand, that stuff is self-leveling.
However, you might try an experiment where you put some Future down on a flat piece of whatever--wood, plastic--and test its dry time. Right before it dries hard, you might place small different-diameter cylinders (sprue pieces, unsharpened pencils, wooden dowels?) standing on end on the surface of the Future, lightly indenting it and leaving them in place til it dried? Let it dry real hard then pull the pieces--it might indeed look like those raindrop ripples?
I would also try it with a thin coat of that same resin you used for the water, and see if that is more "predictable" in holding it's shape-- ifthe Future might self-level after you pull the pieces?