Current stock is CS-HG51-8 and CS-HG41-8. Sorry, no choice.
Excellent choice for bikes with "compact" chainwheels (fewer than 48 teeth on the largest)
It is generally good practice to replace the chain when you replace the cassette.
This cassette will index with any Shimano-type 8-speed shifter, but does require a wide-range (touring/mountain) rear derailer.