Addressable strip allows many different lighting effects, each chip being controlled with a microcontroller reading data on the data line.
WS2811: Voltage of this strip is 12V, is relatively inexpensive, compatible with most libraries, and resistant to voltage drop. However control is for groups of 3 LEDs instead of individual LEDs.
Price is usually listed per meter. Should a specific number of meters be required then please call for a specific quote as the price is may change for above 50 meters!