I am in Upland, CA and have a SR22. I originally put a deposit on the SR20 before the SR22 was made available. Cirrus offered me a discount on an upgrade to a SR22 so I took it. I don’t plan on an upgrade airplane.
There have been times when the extra 110 hp. is really necessary. To my way of thinking, anyone west of the Rockies needs a SR22, and if you look at the distribution on the COPA site you will see that is pretty well confirmed.
Depending on budget, I would opt for a used SR22 over a new SR20.
So far as payload and range is concerned, it is not uncommon for me to see 7 hours of endurance at around 12 gph. after the initial climb in my SR22. While we don’t fly that duration after the initial climb, that extra fuel is a definite safety factor, particularly when you read the distressing frequency of fuel exhaustion accidents.
You are not likely to be operate the IO550 at 12 gph. until precision fuel injectors are installed. These are made by GAMI and have the effect of balancing the power produced by the engine so that all 6 cylinders are working as a single engine. With good balance, fuel flows around 11.5 or 12.0 gph. at cruise are possible with the result of about a 173 kt. cruise speed.
You have the full power available at around 28.5 gph. during take off and initial climb and around 12.0 gph. at cruise which means you can climb out of high DA or terrain airports and then pull the mixture way back for extended range and cool CHTs during cruise flight
The SR22 usually works out to full fuel and 3 aboard with luggage. With 4 aboard and luggage is is basically tab fuel. This is 56 gal. in the SR22 which still gives you a climb and about 4+ hours endurance. This means about a 3 hour or 3:15 flight which is about as far as the endurance of the weakest bladder anyway.
With your mission of about 600-650 passenger weight for 4 what that means approximately that you are leaving out fuel equal to the weight of luggage. You should then have 4 hours plus with reserves, which makes a 3 hours plus flight after climb which equals about 480 nm.
Whichever aircraft you get you should think seriously about oxygen. If you are buying a new aircraft you can get a built in system. I just got a flyer from Top Gun quoting $5,095 installed for the oxygen system. That is too much for me. You can get a 4 place Mountain High or Nelson system for well below $1,000 which is a small amount in comparison to either aircraft.
If you are not instrument rated, you want to take care of that right away. For both insurance and operational reasons, you will be much better off rated.
Most of the new Cirrus sold are the SR22, I think about 80%. With the exception of the engine and the wing extension and the fuel capacity they are essentially the same aircraft. The only major difference is another 110 hp., better climb performance and greater endurance.
You are definitely right to consider the growth factor. Hopefully that will be mostly in the kids, but it definately will occur. With 4 FAA-175# passengers aboard, you are basically at 700# plus luggage. In the SR22 that works out to tab fuel of 56 gal. for reasonable range with reserves.
With the GAMI injectors installed on a SR22 you are basically at SR20 fuel flows but with 56 gal. onboard instead of 26 in the SR20. Plus, with the SR20 you are going to be at the margin of the performance envelope instead of being usually well inside it on the SR22.