Grand Cayman Double Excursion Opinions

[NYdiscuisers]

Hi Dis'ers,
We need to pick your brains on our plans for Grand Cayman. We'd like to try to do a stingray city excursion and horseback riding excursion. Here are some of the questions that we have about this:

1) What time of day is best for each of these activities?
2) Which outfits are best to try and coordinate the two activities?
3) Is this too much to do for one day?

Thanks!