Tell me to mind my own business and I don't wish to be rude to the poster who suggested the foreign rescue, but be particularly weary.
First, of all there are ethical questions with why you would wish to import a dog to the UK when there are already a lot of unwanted dogs there, as well as problems with whether such policies of rehoming abroad merely perpetuate the problem in the home country.
Secondly, there are fewer to no opportunities to meet the dog before making your mind up, so you are really relying on the charity to correctly assess the dog's temperament as well as do health checks.
Thirdly, make absolutely sure the charity has a backup plan if things go wrong. They should have access to behaviourists in the UK to help you if you need it, and foster families in the UK available to take the dog back if things don't work out.
Any decent rescue should include details about the dog's assessment, i.e. is it good on the lead, is it good with other dogs/cats, is it good with children/young children, is it toilet trained, any separation anxiety issues, any chewing or barking issues, does it know any basic commands, etc. Any rescue that focuses too much on a terrible background is pulling at your heart strings - does my heart bleed when I read these stories? Yes, but I don't think it does the dogs any great service to place them in a family that may not be able to cope with them.
Anyway rant over.