I would go with a cast iron skillet or a big f*****' pile of lump (at least one full chimney, better if poured over unlit and allows to get really hot with the lid off) on half the charcoal grate. The lid needs to be clamped down on the big pile o' lump sear to prevent flare ups.
Vortex and SnS, when talking about just searing, are essentially large stainless steel charcoal baskets.
The CI sear grate will give pretty marks but you want sear all over, not on small cris-crossed lines
I like the charcoal rails for exactly this purpose - divide the charcoal grate, and fill half with really hot lump..