My understanding (so this might be complete rubbish...) is that BWoS have 'lost interest' in Typhoon, and are much more interested in JSF these days.
I'm not quite sure what is meant by the idea that some aircraft would be 'converted' for ground attack, though. The most obvious answer is that some of the squadrons earmarked for the AD role will simply change to OS or multi-role - but I suppose that we could be talking about additional/different systems? Or maybe, at a push, having some two-seaters?
The big question, though, is whether any of the funding for the Tranche 3 aircraft would be released for the purchase of alternative platforms. Past experience suggests that the cancellation of 88 [I think] Typhoons wouldn't mean that a similar number of alternative platforms were purchased. I suspect that most of the cash earmarked for this purpose would go elsewhere.
If the money is available, then I guess that JSF might well be the answer - Gripen might be a dark horse - but Jackonicko is probably better placed to argue the case for this than I am.