Of the choices I'd pick the standard Stainless grates and a solid steel or cast iron griddle. You don't need the griddle, but if you're reverse searing it's hands down the best way to get a hard sear quickly. If you're having trouble with too much char with your griddle then consider the reverse sear method where you slowly cook the steak on the stock grate until it hits the desired internal temp (rare, med-rare etc), then pull the steak off and open the fire wide open with the griddle. Once the griddle is reading 600F+ with a laser themo drop your steaks on to get your sear. It's called "reverse sear" b/c you sear at the end.
Grill Grates are too thin & wimpy to pump out and maintain the same level of heat as thick steel or cast iron. I think they're great if you're stuck with a pellet cooker but if you're cooking over live fire there's much better options.
Cast Iron grates just burn in grill marks before the spaces between the grates have enough time to properly sear. Plus they rust. You don't want grill marks, you want an even sear over the entire surface. Leave the grill marks to Applebea's.
Obviously this is all my personal opinion.