Hi FBech, wellcome to the forum.
I see you have quite nice not small room, nearly 20 m² in my continental metrics.
Also your integrated Technics receiver has quite lively, for sure not borring sound with solide control over speakers.
If you have space in your room I will recommend to choose floorstander version of Dali Oberon 5, also QA Acoustics 3050i will work very good in your room. New generation of QA 30XXc speakers has quite different sound voicing from older generation and price has also moved higher.
My personal choice of speaker for your room, your rock music, your Technics receiver will be ... Triangle Borea 07. I am not sure if those speakers are available in your area, in UK is this french brand more and more recognized. And they deserve this attention. This speaker is lively, has a lot of energy, detailed sound with also power in bass. For rock(even metal) they are very good. But not only for rock for sure. They are not dry, technical, borring sounding. And they have bassreflex on the front, so they are easier for positioning in your room, they can stand nearer to the rear wall than QA 3050 or Dali Oberon 5(7) - those speakers with large rear bassreflex need more space to the rear wall to prevent boominess in sound (bass). But also QA and Dali are excellent speakers. Wharfedale is not my cup of cafee. Smaller bookshels will not make such a good job in your size of room, they will lack deeper bass. Bookshelfs can for sure sound with good bass but from higher price range (like Kef R3 Meta).
And pls. do not use some cheapest phoneline cable to connect speakers. On such system you will hear already difference between cables. You can try e.g. QED speaker cable or similar. BR.