I have >10,000 miles on an S with premium audio, and >10,000 miles on an S without premium audio.
I have >10,000 miles on an S with coils, and >10,000 miles on an S with air.
Ultimately this is up to what you value most, but:
-As others have said, audio can be upgraded (can anybody say Reus?!?) first time around I went with upgraded sound (it was $950 at the time) but I wasn't entirely happy with it because of certain frequencies distorting. To my knowledge this is still the case with today's upgraded sound system. I went with the basic audio and upgraded to the Reus system. Suspension cannot be retrofitted.
-Air suspension technically improves aerodynamics at speed, but based on my personal experience and what I've heard from others, this difference in efficiency is imperceptible given all other variables (wind, temps, etc.)
-Suspension height is not a problem with coils or air. However, the drawback with air is that you explicitly have to raise the car with air, whereas coils always ride slightly higher than normal setting on air car. I scraped bottom probably 4 or 5 times with air, and have never scraped with coils.
-Air is more expensive, complex, and maintenance is potentially much more expensive.
-Air is heavier.
-Most think air is slightly more aesthetic, because the car rides lower.
-Coils are a bit stiffer...more of a sporty feel.
I had this same decision to make. I went with basic audio and upgraded to the Reus system because sound quality was more important to me, and I wanted to avoid the potential maintenance costs of the air system.
If I were you, I'd look at it this way:
-If the look of the slightly raised coil car (compared to air on low) or a slightly stiffer suspension doesn't bother you, go with the premim sound.
-If there's a possibility you might later spend a few thousand dollars to upgrade your sound system and potential maintenance costs or the air system don't worry you, go with air.