Both the satin and angora genes are recessive so these kits should only have one satin gene from the buck and one angora gene from the doe.
You need to breed a brother to a sister for a 1 in 16 chance of getting a satin angora, however it may not be a high quality satin or angora as there are other modifiers that improve the quality that will be trickier to breed for and likely take several more generations.
If you breed back to the doe you should get 50% angoras but zero Satins and no way if knowing which kits carry the satin gene
Same thing if you breed back to the satin - 50% Satins but no angoras although you might be able tell as sometimes the angora gene does change the coat consistency.