I don't think stealth is a requirement for SFC otherwise it would be mentioned. MOD won't accept another type of strings-loaded 5G fighter that too just 40 as a separate command. If stealth was indeed the requirement, then MOD will press SFC to wait for FGFA till 2018.
The problem with stealth fighters in this regard is the weapon bay, because they often have very limited space, which makes it not possible to carry big weapons internally. My guess is if a stealth fighter in this role, than it have to be a stealth UCAV!
I am still strongly supportive of getting Su-35BMs if SFC cannot wait for PAKFAs to join their ranks. Those birds are seriously LETHAL: they have huge payload capability, AESA option and share similarity with MKIs making our work easier. Su-34 is also a secondary option. But I don't see another more reasonable option and certainly not Rafale.