I've looked high and low (in the UK where sudoku is currently very popular) and never found one. To be honest though, angusj.com augmented by simes.clara.co.uk gives you everything you need to be able to solve all difficulty levels up to and beyond Pappocom Very Hard.
From your current posts in other forums here, you seem to be at the point where I certainly once was, and where I suspect most players would have been at some stage on their personal learning curve, that is to say finding it difficult to see the subset needles in the "pencilmarks" haystack.
As I've said in another forum within the last few days, this particular aspect of sudoku solving essentially requires "patient sleuthing" rather than logic as such, and it's therefore of paramount importance that you know not only exactly what you are looking for but also how to arrange your data to facilitate the search.
I'll leave you to think about that latter aspect yourself, so that I don't rob you of the confidence you will ultimately gain by getting there "under your own steam" but what I will say, as a hint, is that the Pappocom and other "left to right type" pencilmark layouts within a cell are arguably not the most helpful when searching through a range of such cells.