The reasons for horses and ponies being in the rescue sanctuaries can be varied and not all of them have been abused or neglected ..... some some in because owners may be very ill or have died ...... so you might be able occasionally to get something rideable straight away.
I am a trustee for Equine Market Watch and we are in the west midlands so feel free to look at the website
and you would be welcome to come look around to just visit.
EMW would want to ask you loads questions to make sure you knew what capabilities you had to take on an appropriate equine companion and would need to visit where the horse / pony would live. If everybody happy then you would have one on permenant loan and if any problems the horse / pony would come back to EMW .
You need to be honest with yourself as well as the organisation about what you expect and what you can realistically deal with. We would also be honest with you about any issues we are aware of but we do try to "solve" all issues as far as we cen first . John Jones works with many of the horses and advises us on an ongoing basis ..... we aslo have several complimentary therapists that volunteer their services on a regular basis.
EMW also has students from the local agricultural college to do the equine welfare part of their qualification and young people here on work experience.
My own horse was a rescue form another centre before I became involved with EMW and she was physically OK but had been abused and it took a long time till she was considered safe to ride .... yet now my grandchildren can play all around as well as ride her .... and we drive as well.
hope this helps