Base4 in CT are pretty good, although they are often quite busy, so book in advance. I don't know whether they run R22s, but they definately have R44s.
Whether you can do the R44 rating there depends on your licenses. If you hold a SA PPL (ie. you qualified there), and hold a UK PPL on the basis of the SA one (ie. the UK PPL is a validation of the SA one), then you could (probably) add a rating to the SA license, then get the UK CAA to reciprocate on the validation (with, no doubt, the payment of wads of wonga).
On the other hand, if your primary license is a UK (JAA) one, and you're flying in SA on a validation, as the school in SA is not a TRTO for the UK CAA, the training can't count towards a license. The best you could hope for would be to get some training from someone who knows the UK syllabus and use that to bargain for a 3-hour type-rating from a school in the UK. Remember that to get a 3-hour TR, the school has to be licensed for it AND have it written into their AOC and ops manual; not everyone has this exemption. You also have to convince them that your training overseas was of a high enough standard that they actually don't need to take 5 hours over getting you through.
If you're planning route 2 above, I'd strongly suggest doing LOTS of planning and phoning around first!