Thanks again for all of the advice! I will definitely check here for opinions before making any purchases. Out of curiosity, I've had the option of taking equipment for demo from ski and tennis shops in the past. Is that also common practice among dive shops?
No, but rental programs are common. Its a way to try gear before you can buy. If you are concerned about the sizes or quality of gear on a trip, its a way to know that its taken care of before you leave. The downside is now you have to carry the gear with you when traveling, which nowadays can lead to baggage fees.
An exception is that WW carries a limited number of Cochran Computers for DAN research. I own one myself, and is a computer that can grow with you as a diver if you go into more advanced types of diving.