I am not an installer, but I
do live in the Phoenix area.
Your client should obtain a 75e elliptical dish ("oval", per Iceberg's post) and quad LNB (the current setup offered by Shaw) for use in Phoenix. The smaller dish that Shaw offers (the 60e) may not be large enough to provide a reliable signal in marginal weather (which doesn't happen often here). The quad LNB for the 75e is as pictured in Iceberg's post (without the wood and the second LNB

). Note that the LNB must be matched to the dish, i.e., the 75e dish requires a 75e LNB. The LNB number is printed on the back of the case.
Even with the 75e, signal may be lost briefly in a very heavy rain shower, but not in moderate rain.
I have installed my own dish on 2 occasions at different residences in the Valley. It's a breeze, even if you only use the meter that is built into the receiver. A graphic of the pointing azimuth can be obtained from Dishpointer.com, but is also 178 True or 166.8 Magnetic at my most recent install. For starters the elevation should be set at 50.8 and the skew at 88.3 (again, figures are at my location). The receiver does not need to have been activated to use the built-in meter. It is recommended that you set the receiver to channel 299 for pointing the dish. The signal meter is found at Options 6-4-3-1 on the most-recent receiver models. Enter "4128" in the EMM Provider Box; once entered, a green box indicates that you are indeed on the correct satellites. The satellite number on this screen should then read "A4"
Once the signal has been found and the signal level optimized on 299 (mine runs in the 70's most of the time), the receiver can be activated by Shaw and then you can fine-tune the signal using the EcbNo's for a channel from each of the 2 satellites, e.g. 299 and 701. The location of the EcbNo screen will depend on the model of the receiver that your client has.
Let us know how it goes.....