A better picture would be that of the mower; I'm pretty certain that the motor(s) you picked out for it are -way too small- (not too mention too slow) to even think about moving a mower with a 6 HP engine (not a small mower). You need to be looking at much larger motors (and of course, much larger motor controllers); likely both will put you outside your 50 euru budget (unless you are very good at shopping surplus or junk picking for the motors) - unless the 50 euro budget is for -only- the motor controller?