No need for a new cassette, just remove and put it on the new motor wheel
Between the previous 2024 Cube Nature and these 2 disc braked boardmans which would be your pick to convert to e-bike:
Boardman DRC Hybrid 8 yrs old, good condition, carbon forks, sram gears, serviced gears and brakes recently, says it was £800 new and asking approx £180
Boardman X7 Hybrid 7 years old, good condition as stored indoors, suntour nex fork, 3x9 sram x5 gears, tektro auriga brakes, asking approx £180 also
Which of the 3 would you prefer to convert, or are they all in the same ballpark in terms of reliability/ suitable to convert?