Billy,
I think impregnated maple (aka futurewood) is probably going to be the best alternative for Dymondwood.
That process adds color, weight, and dimensional stability to the wood, plus it's not brittle like Dymondwood is.
And it's a better material than plain old actionwood IMO.
The cool thing about it is that most guys can do it themselves on a small scale if they want to put a little effort into getting set up.
Mike Miller (aka CrookedStic) is the best example that I've witnessed of that. He's posted all kinds of stuff about the process on TradArchers.
I've also heard (but can't confirm) that the guys at Hunter's Niche/Predator bows sell futurewood to other bowyers.
Those guys have a lot of experience making impregnated maple and they're probably set up to do it on a larger scale than most of us "garage bowyers".
I'm pretty sure that they currently produce all of Bear's futurewood. That's saying something right there!