Hmm. I am not one to mix food metaphors. Oyster sauce reads as Asian to me (like soy, which I never use for non-Asian recipes). Your preference though.
Were it me, I'd likely serve a thin, simple
vinegar sauce on the side (I always serve sauceless, sauce on side) and, for those who like thicker, more typical sauces, probably a
KC-style, or perhaps something fruitier, like a
cherry sauce (I am a big fan of fruit, smoke and meat as a combo). Another, tomato-based but simpler, would be Steve's
No. 5 sauce.
Though I never sauce ribs while they cook, I do like a sauce or two (sometimes three) on the side for drizzling/dipping. I am a fan of complex flavors so tend to go that route with one or two, and make another of the simple variety.
Just a thought.