The only rifle powder I've ever seen, heard or personally used for light loads is H4895. Look over at Hodgdon's sight for formula. I personally wouldn't use any other rifle powder for reduced loads.
Pistol powders however are another story. I've personally used Trailboss, BlueDot and SR4759, Unique is also popular but I've never tried it. If you go over to the forums at 24hourcampfire there has been many threads concerning reduced loads with pistol powders in the past few years. It may take some work to find em but may be well worth your time. Look under Reloading: Varmint Rifles.
No matter what you're gonna need a different powder but it may well be worth the effort. Keeping things simple is Trailboss and H4895. Both have formulas of at Hodgdons.