I've never flown a Cirrus, but from all accounts they're capable and good planes. It does make sense to train in the aircraft you're going to own. However, if you're planning on grass strips etc, then the P210 might be a better choice as the SR22 isn't great on grass. The P210 is a complex aircraft that will need preventive maintenance, but not excessively so. Good aircraft with a big owner base.
If you want to fly 4 people and have any kind of range, you'll need to buy at least a 6-seater. That limits your options. Any kind of night flying over barren terrain - mountain or not - is maniacal in a piston single in my mind. If it quits, you have very little chances of a happy ending.
But if you want it - go for it! Flying and aircraft ownership is magical and highly recommended, albeit not the cheapest of endeavours. But owning a plane is still cheaper than your average coke habit!
