Marinade as you wish (I like red wine, crushed garlic, chili flake, thyme and olive oil)...also like to rub mustard on the outside.
i'd start direct, bone side down. By that, I mean if you're laying it flat, the rib bones are arc-ing downward. give it 4-5 minutes, then flip and another 2 minutes or so. I cook by feel, so you want the meat pretty soft to serve med rare.
one thing I've been doing is actually deboning them, which is pretty easy. just run your knife along the bone, kind of "scratching" it away and the meat pulls off pretty easily. Do the marinade thing...cook 2 minnutes a side or less even. The reason for this is you get a nice crust on two sides instead of just one.
Let us know how it turns out.