Hi alzak
Penac P is just silca, plain sand - no value for plants
Penac W is over 90% of CaCO3 plus some MgCO3. Dolomite from garden shop will do better job as contains more MgCO3.
Bacter is just bacteria, and can be replaced by other similar products or mulm from filter cleaning.
If you are going to replenish existing substrate with nutrients go for Osmocote or similar product with slow releasing nutrient properties or you can add it to the new one to counterbalance for Power Sand.