If you pop your postcode into:
It will give you your exchange. Let us know which exchange, and we can help to make a more informed decision. I assume it's this one,
but please confirm. By the way, you have to pay landline rental if you want broadband on the landline.
Personally I use Plusnet for rental, call package and broadband (extra, which is 60GB peaktime per month allowance, and is reasonable for all uses). The whole thing costs about £30 per month assuming I don't make international or 0871 type calls. You may want to consider international calls in your decision making, if you still keep in touch with S. Africa.
Like I said, find out your exchange. My setup is ADSLmax, but you ought to get faster than that if I've guessed your exchange. A fibre RFS date (September) is imminent.