A save the date is similar to an invitation and is mailed up to one year before the wedding date. Save the dates simply announce that the wedding date has been set and encourages recipients to plan for the event. It is not used as a substitute for the wedding invitation and typically mentions that an invitation will follow.
Save the date cards are a fairly recent invention, so there is no standard for proper wording. The best approach to take is to decide what you want you're save the date cards to do: simply let people know that a wedding date and location has been set, inform them of transportation or accommodations, or act as an itinerary for a wedding weekend, with details for each of the activities that are planned.
Once you've established what you want you're save the date to do, writing the words will be easy. Most brides simply send out a short wording indicating the bride and grooms' names, the date and location (the city, not the exact location) of the ceremony, and the phrase "Formal invitation to follow."
Wording for the wedding invitation is trickier, by far. Most couples who host the wedding themselves choose something along these lines. (Note that this wording is generally used with ceremonies held in a house of worship. For a non-religious ceremony, replace "request the honor of your presence" with "request the pleasure of your company.") Generally the Save the Date is just that a notification for the guest that you are planning a wedding, date, where it will be, also that they can expect an invitation to follow.
When you plan your wedding, the hotel or venue will know that you won't have exact numbers and won't expect any until you get closer to the date. I'm afraid that if you ask for an RSVP for the STD, people may mistake this for the invitation. Set up a website and invite guests to visit it and you should get a pretty good idea from their comments, who will be able to come.
When my clients do STD, I like to include all the hotel information as well as any other travel related info they may need. This will give guests the information they may need to know if they can afford the trip. Include room blocks and costs as well as any cut off dates, and phone numbers for guests to call and make their reservations. Also invite your guests to visit your website for updated information. This is a good place to list your registry and any other information you'd like your guests to know.
Planning from out of state can be very difficult. If you don't have a coordinator in Arizona, I would recommend it. They can save you a lot of hassle, worry and stress. With a coordinator in Arizona you will be able to deal with all of the other things that you have going on and he or she can take care of the wedding things in Arizona. Just make sure that you keep in close contact with your coordinator so you both know what you want and not show up at your wedding with something that you didn't want as your theme, color, etc.
Just make sure that you go down and see how everything is going a week or so before you walk the isle. That way if you don't like what you see then you can have that changed and there won't be any running around and stress on you on your big day.