from what u are saying it sounds like u already have a t series housing. If this is the case u only have 1 real option, get a kaaz, cusco or trd centre for it and live happily ever after.
As for the hilux diff, it would be unbreakable in a sprinter. But u cant make a hilux centre (F and G series?) go in a t-series home...
You would have to buy the whole diff and mod it as above, then if u want a nice lsd for it, ull be up for more $ again, however factory LSD's are common, but no where near as good as a trd, kaaz or cusco diff.