My SDS drill that i use for core cutting is a Ryobi 650W currently £39.99 from screwfix. Have done a lot of Ex fans box chiselling etc. 3 1/2 years old and now realise That if I'd greased the SDS connection it wouldn't be squeaking at me now. that drill has made it's money many times over and has clutch hammer and normal . You could do a lot worse.