How much are you currently spending on ADSL?
If you are paying close to R1000 per month already then the Rain offer seems reasonable to me provided that you can get decent reliable speeds. I would far prefer Rain 5G over DSTV which is a similar price. I am in the process of moving over to Afrihost Pure LTE but they only offer small capped accounts which becomes expensive quickly if you require large amounts of data.
Lots of fibre customers have switched to Freshphone for cheap Voip services. You are only charged for the calls that you make. The rates look very good to me. If you want to port your existing number in December you need to do it very soon as the cutoff date is 13 December otherwise you will have to wait until January.
Port your current geographic telephone number for a once off cost of R150 including VAT.
www.freshphone.co.za