I want to shear my own sheep, which machine do I need?
Mains 240 volt
If you always have mains power where your sheep are then a 240 volt machine will do. Always use a Circuit Breaker, and keep any extension cables up out of the way.
If you want to use the machine away on the hill, or in the field, use a battery powered machine. There is a range of battery powered machines now available. These should be safer to use, and can be used in the field, from a vehicle's own battery, or a spare battery. Some now work off a rechargeable battery and are fully portable.
For either, you need a machine powerful enough to cope with the numbers and breed, and the timescale you have to complete the job..
Finer Wool sheep such as Texels and Suffolks and lustre wool such as Wensleydale and Teeswater take more power than more open wool sheep like Swaledales.
Similarly, if you want to do them all in one day, you may need a more powerful machine than if you shear a few over several days.
Are you intending to shear a lot more sheep in the next few years, or stay as you are?