Two major types of outdoor fence and deck wood preservatives which of course can be had tinted so as to do double duty as a stain: typically there's the water-based and then there's oil-based. My experience has been that the oil-based preservative-penetrants so much better with much less surface build. If you can still find it, Flood's Penetrol (or something similar) would do be my choice on the cedar and it would preserve the color well. BTW, no matter what the salesman tells you, plan on maintenance re-coats every two/three years. Oil-based penetrants work well in this regard, requiring very little surface prep prior to re-treating, compared to other-type finishes.
