I don't know where you live or who your LDS is, but the one I use is near Manchester
Divelife and they sell quite a few snorkeling packages as well as the items sold individually.
The most important item is the mask, because a poor fitting mask which leaks will just make for an irritating experience, so you need to try on quite a few masks to make sure it fits. If you are just snorkeling go for a snorkel which drains and has a "floppy" corrugated section which will me much more comfortable.