What kind of pavers hold up for widening a driveway?

I did almost this exact project a couple summers ago, a 20 inch strip along one side of my slab so my truck door wasn't hanging over the dirt. Went with 60mm pavers from a local supplier and they've been totally fine with tires rolling on them regularly. The 80mm stuff is really for full driveways taking constant vehicle traffic, so for an occasional parking strip the 60mm is plenty. The big box store pavers will work, just check they're actually rated for vehicle use on the label since some of the thin patio ones aren't.

For the settling issue, the trick that worked on mine was digging out all the topsoil under the strip, not just scraping the grass off. I went down a few inches to firm ground, tamped it, added gravel and compacted it in a couple of layers, then set the pavers so they sat maybe a quarter inch proud of the slab. After a winter of freeze thaw they dropped flush and have stayed there. Also throw down some paver edging spiked into the ground on the grass side, that's what stops the outside row from wandering. I skipped the grass grids myself, too fiddly to trim around.

For the gravel vs pavers question, I did a gravel strip at my old place and it worked fine for holding tires, but every time the tires rolled on it I was kicking stones into the garage and off the lawn for months. Ended up switching to pavers and wished I'd started there. One thing that made mine hold togather was polymeric sand in the joints. It locks everything up so the edge pavers don't wander apart and weeds don't sprout through, which was a constant battle with the gravel. Sweep it in, wet it down, done.