I can't imagine Sirkorsky hasn't had this in the works for us. We just balk at the cost when it comes up and short of a Garmin on the glare shield, they've got us over the barrel.
At my last squadron, we took a -60 down to a Garmin installer and he looked over our system. He said it could have integrated a Garmin system (I'm not sure which one but it would have been IFR capable) for the cost of what it would normally cost in the real world. Obviously Navair would have had to have their chop on it, which I'm sure would have increased the budget by at least 3 times.