I need to replace my SRAM PG850 8 Speed 11-32 Cassette & Chain on my Giant Defy 4 2015, due to general wear and tear, however I would like to upgrade to something a bit better though within budget (about £50).

\*It needs to be Compatible with my Shimano Claris Shifters and Derailers.

Any suggestions or advice on what I should be looking for would be great. This is the first time I have replaced anything on my bike, so I have a limited knowledge of what parts go with what.