Dear Richard
 
Thank you for your enquiry.  Your space is just about adequate for keeping 2 sheep and we do sell them in small numbers.  However, we would not sell a sheep to be kept by itself.
 
Having said your space is big enough, there are other aspects to consider:
You will need to register with DEFRA (Dept of Food and Rural Affairs) as a keeper of sheep and they will issue you with an Agricultural Holding Number. Without this holding number, nobody can get a licence to move sheep onto your property.
 
Sheep have a complex annual veterinary care routine and this could be very expensive if you have to get most of it done by your Vet.
Over time there will probably be a build up of parasitic worms on your grazing unless you have the ability to leave it ungrazed by sheep for a year.  Hence a strategy for minimising any worm problem has to be adopted and implemented.

They need regular worming. They need an annual vaccination against clostridial diseases. They fall sick very easily with a host of illnesses.  Their feet need regular trimming. They need to be sprayed every six weeks in the summer months to prevent blow fly maggot infestation and without it, the maggots will eat the sheep alive and kill it.

All the veterinary medicines, sprays, injections etc that will be needed come in time limited packs,  sually sized to treat at least 20 sheep. The  alternative is to get your Vet to do all these regular treatments for you but this could be very expensive.
They have to be shorn once a year and this is best done by an experienced shearer.

In the winter they will need shelter and straw for bedding and when your grass becomes inadequate, which it will except in the spring,  they will need feeding with hay and a ration of commercial concentrates.  Hence you will need the ability to store these items.

You will not be allowed to move your sheep off your holding without a movement licence issued by your local Trading Standards office.

If you need to move your sheep, the current regulations are that it can only be done using a livestock trailer or lorry and it must be pressure washed and disinfected each time it is used.  In the very near future you will need a certificate of competence in animal handling before you can move your sheep. Big Brother is alive, well and infiltrating all aspects of agriculture.

I hope I haven't put you off the idea of keeping sheep.  All the problems listed above can be dealt with but I would not want you to embark on shepherding without having thought through the possible pitfalls.