There are no dumb questions.........:smileyhappy:
I am glad you asked that question------------this is one caveat you would need to considder.
You can mix and match different IAP models in the same cluster. If you went with the IAP-103 you would get AppRF on the -103's but not on the -9x. The different models all run the same version of SW; however, different IAP models have different SW images. You would need to upgrade the SW on your IAP-93 to a version that the IAP-103 supports. The minimus version for the -103 is v.4.1.0.0.
PLEASE NOTE: The IAP-9x does not support the initial release of v.4.1.0.0 so be sure you do not upgrade to that version. We are looking at adding IAP-9x support into v.4.1.0.1 soon. So, this is one issue you need to be concerned about. Otherwise, you could look at one of the other IAP models that don't need v.4.1.0.0 like the IAP-115 ($895 US). You could also deploy the IAP-103 as a second cluster until such time that v.4.1.0.1 is available.
The other issue to be concerned with is that the IAP-9x is a single-radio AP. As such, you can do 2.4GHz -or- 5GHz....just not both at the same time. The IAP-103 is a dual-radio AP so you can do both bands simultaneously. If you mix these in with the -9x you could have coverage holes on the bands that the -9x's are -not-supporting. Say, for example, the IAP-9x are all supporting 2.4GHz. Now you add one IAP-103 at one end of the building and one IAP-103 at the other end of the building. If a client attaches to the IAP-103 on the 5GHz radio then gets up and starts walking to the other end of the building there may be a 5GHZ "hole" in the center of the building. The client would do one of two things: drop and re-associate to the -9x on 2.4 or hang on to the first IAP-103 for dear life before finally deciding to roam to the second IAP-103 which would cause performance issues. NOTE: Roaming is a decision the client SW makes and not the AP. We do have a feature called "ClientMatch" that does help steer the client to the best AP but, ultimately, it is up to the client.
In terms or "rate v. range" that is a discussion to avoid. Simply put, every environment is different. Walls, construction materials, RF "noise", etc, will all affect performance. If you want a general rule of thumb go about 2,500 sq ft per AP and this should be good enough for voice (depending on the environment) and up to around 3,500 sq. ft for general coverage.