Hi CrazyTown,
Welcome to the Mattress Forum! 
The first place I would start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones.
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability, durability, and value.
You can see my thoughts about airbeds in general in this article. While any mattress can be a good match for a specific person because each person’s needs and preferences or the criteria that are most important to them can be very different … in general terms I would tend to avoid them unless there is a very compelling reason that an airbed would be a better choice for you in “real life” (outside of the many “marketing stories” that you will hear about them) than the many other options or types of mattresses that are available to you.
If for some reason you are committed to an airbed and you are convinced that there are no other types of mattresses that will meet your criteria then there are some other airbed options available to you that are listed in post #3 here that may be in a much better quality/value range than the Sleep Number you are considering.
I would treat the purchase of an adjustable bed and a mattress as two separate purchases so you can choose which one of each you prefer and make apples to apples comparisons with each of them instead of being locked in to a combination where you may prefer either the mattress or the adjustable but not both (unless of course you would purchase the same mattress and adjustable from the same store if you were buying them separately anyway or you are receiving a discount for buying both that would make purchasing the combination purchase worthwhile for you). The same mattress will “work” just as well on any adjustable bed.
There is more information about choosing an adjustable bed in post #3 here and the main adjustable bed topic that it links to that can help you choose an adjustable bed based on price vs features comparisons and also includes some retailers that you can use as good sources of information about the features of the adjustable beds they carry and as pricing references as well (in post #6 in the main adjustable bed topic). Of course there are many other sources as well and prices can change on a regular basis so I would also include some internet searching in your research. I would also keep in mind that online advertised prices are often price controlled so make sure you call the stores you are considering to find out their best prices rather than just looking at websites.
I would also be very cautious about using other people’s reviews or experiences on a mattress (either positive or negative) as a reliable source of information or guidance about how suitable a mattress may be for you or the durability of a mattress and in many cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person may be completely unsuitable for someone else either in terms of suitability and PPP or in terms of durability (see post #13 here). Reviews about the knowledge or service at a particular store can certainly be helpful but when it comes to the specifics of a mattress they won’t provide you with the type of reliable information you will need to make an informed choice about how well you will sleep on a mattress, how long you will sleep well, or the “value” of a mattress purchase compared to all the other options that are available to you either in your area or online.
If you let me know your city or zip code I’d also be happy to let you know about the better options or possibilities I’m aware of in your area.
Phoenix