Commercial - Most basic, You can get anywhere from close to the center cuts to all the way at the edge cuts. Basically a lucky dip.
Provincial - Uses the #20 sponge on most of them for more consistency in the sponge hardness and thickness, also elasticity is improved. Topsheet is also much closer to the center cuts compared to the Commercial.
National - The big daddy, best of the best. Topsheet is from the dead center. Guaranteed to be close to perfect in terms of elasticity, speed and consistency. Very supple compared to the other versions. The sponge on the national is never the same for each player, some have custom sponges put on to their liking. To say that there is a "Universal" H3 national is completely wrong.
The only way you can obtain them is through highly regarded contacts *ex coaches and so on*. Even then your paying stupid money for them. Nowadays DHS is cracking down on the leaking out of these rubbers, so players are forced to return their old sheets before they can get a new batch.
Bottom line: Buy the commercial one off a reputable dealer and you'll be fine. Going to such lengths to obtain a single special rubber is absurd.