You want redundancy, with pitot + AOA. Which failure modes are you trying to protect against?
- Blocked pitot (icing, mud daubers, etc)
- Bird strike
- What else?
Possible architectures with both pitot and AOA:
- Dynon pitot/AOA tube
- Heated pitot + separate AOA system (e.g. Proprietary Systems)
- Dynon pitot/AOA tube + second heated pitot
Option 1, while somewhat popular, doesn't protect against either pitot icing or bird strike. The Dynon AOA needs the pitot pressure to work, so pitot icing will kill the AOA and airspeed. It also does not protect against bird strike, as both functions are on the pitot tube. Also note that the currently available Dynon pitot is not heated, although they are working on a heated version.
Option 2 does provide protection against both pitot icing and bird strike, but it means yet another indicator to mount somewhere.
Option 3 does provide protection against bird strike, but still doesn't cover you for pitot icing. If the heated pitot ices up, the non-heated Dynon pitot would also be iced up. This option also forces either two ASIs, or a valve to select between pitot sources. Complicated. Heavy. Expensive.
Realistically , what are the odds of pilot icing, if you have a heated pitot tube? You would have to have pitot tube heater element failure, and be in icing conditions. You should be trying to avoid icing conditions, and it is possible to check the pitot heat before each flight. Don't worry about this one.
A bird strike on the pitot tube is possible, but that is a fairly small area to hit. Not too likely. Birds that see you are coming dive, so they wouldn't hit the pitot tube unless you were upside down. And, even if an unlucky bird knocks off your pitot tube, I'm betting you will still be able to safely land the aircraft without the ASI, unless this happens before you get to know the aircraft.