Don't know why but it's still under construction. Patiente dear Watson!!!

There is no any rule or law which orders diving equipment to use. So you can use the equipment which refers to your diving school or system.

Following text is just my recommendation. It is not a regulation nor an instruction manual.

No matter on a year time or season most of the waters in Czech Republic are very cold. For providing temperature comfort it is recommended to use dry-suits, hoods and gloves.
To avoid the waste of breathing gas (Out Of Air situation) it is recommended to use regulators established for cold waters (such as Apeks, Aqualung, Poseiod, etc.) and to use two independent 1st stages of regulator. That means use a single tank with two valves or rather use twin set (double tank).

Take a look at the following pictures and inspire yourself with organization of the equipment: