Kat - I guarantee that you will snorkel again - it's quite a unique and enjoyable experience, and one that you don't know what you're missing until you've done it. That crystal clear water, the outstanding colour, the motion of floating in the water with your head immersed, the awesome nature of the world down below...........
I, like you, take no comfort in some of the cleansing processes used at various ports. We bought our set of mask and snorkel at Canadian Tire and rented to vest and fins. They are usually able to be rented in individual pieces. Keep in mind though, that unless you can find a vest sufficiently filled with air, you'll need to blow it up yourself. We have priced these snorkel life preservers and they are quite expensive (about $99 Cdn) - we may invest as some point.
Make sure you don't get a set that is too cheap - a poor mask that allows water to leak in will ruin your adventure . With salt water stinging your eyes and the goggles fogged up, you'll not be able to see anything. I will try to look up the name of the set that I bought and will post in the next day or two. It was $80 Cdn for the two piece set.
Hope this helps. Enjoy your experience!!