I would use alfredo sauce. But when I make anything with alfredo I usually first add about 1-2 TBS. extra light virgin olive oil to a pot, then add some minced garlic, and chopped or minced chopped clams. Just stir for a couple of minutes, (I use a fairly high-sided sauce pan as the sauce with oil/garlic/clams, then white wine with alfredo added tends to bubble up if not constantly attended to, or if heat is not turned down to med-low), then add just a touch of whatever white wine I have on hand, cook it down a bit, then add the alfredo, and add some fresh ground black pepper. Stir until well combined and aromatic-just several minutes. When done, I add chopped fresh parsley. Spoon a couple of large serving spoonfuls on the botton of the serving platter, drain ravioli, then add the ravioli on top, in a single layer, then add the remaining sauce on top, followed by the rest of the sauce and a generous sprinkling of fresh grated parmesan cheese and another sprinkling of fresh parsley.
Ocassionally I've added chopped up sundried tomatoes at the same time I've added the clams. The zing of the tomatoes adds a nice touch and somewhat lightens, along with the wine, the heaviness of the alfredo sauce.
Red pepper flakes or a crumble of italian sausage in place of the clams added to alfredo would work nicely too.
Enjoy!