Matching tires is great if you spend more time showing off your ride than actually riding it, otherwise mismatch to your hearts content!
There are some effects of mismatched weight though. Bike handling will change slightly as more weight is rearward. Since your riding AM/DH, this is a good thing as it will give you a little more stability on the downs. On the other hand, it's going to mean that the front end will lift a little easier on the ups.
Same problems will affect you in the air, though to what degree depends on your riding style.
These both depend on your riding style and how sensitive you are to changes in your bike's weight/handling.
As a side note, if you have problems with both pinch flats and sidewall/tread cuts, I'd recommend the dual tube/tubeless setup. This allows you to pinch a tube, or seal a cut and still have a tube for air. Also, look for tires with a higher durometer (rubber hardness) which should be less prone to punctures, cuts, and deformation.