I have been brewing cider like this for a while now - always get a very good result. I always brew 19 litres or therabouts as I keg the cider. Always bulk prime with 165g dextrose per keg (19l).
I first tried the coles smart buy apple juice, I think I used 12 litres, plus 6 litres of apple and pear (Berri)
champagne yeast
Next I tried the real apple juice from the supermarket - was a bit more expensive. Once again, I added pear juice and I found the result was not as nice as my first attempt, so I went back to the cheaper juice.
Since then, I have also tried adding about 200g light dried malt - it added a bit of body and flavour and I will continue with this practice.
I have also tried adding 2 teaspoons of mallic acid - makes it a bit tart and is supposed to bring out the flavour of the apples. All I find it did was make it a bit tart, but I liked it, try one teaspoon at first if you want or leave it out all together. If you brew into bottles I guess you could try adding it to a few bottles at the bottling stage (not sure)
I am yet to try putting actual apples into the brew, but will do so soon. What are others experience with this? should they be pulped and steamed first to sterilise
In summing up, I think my best result is with the coles smart buy apple juice, champagne yeast, 200g light dried malt and 2 teaspoons of mallic acid. Out of a 20 litre batch, I have about 3 litres whole pear juice, or 6 litres of berri apple and pear.
Good luck