The sulfur smell is most likely sodium sulfide, a common ingredient in fixer. My older fixer has this problem of the sulfur compound separating out of solution. I wonder if the problem is this "new" fixer" has been sitting around too long? Hmm.
Regarding Ilford making a special paper-negative product, at one time I had asked an Ilford contact via the APUG forums (Mr. Simon Galley) on the prospects of an RC version of Harman DPP, and he nixed the idea right off. So don't hold your breath on a special paper negative product.
Personally, having worked extensively with both paper negatives and Harman DPP, I'd rather see an RC version of the direct positive paper, since that would open up the prospect of doing "instant" street portraits (develop, fix, quick rinse and dry in less than 5 minutes). Kind of like a wet polaroid process.
~Joe