It's unlikely any of these would be invasive in your zone. Heights vary from under a foot to a good 4-5 feet, although there are some which will go much taller, like a variegated Arundo.

I thought at first they were the same variety but now I’m not sure. The smaller one at the right in the second picture has much more white in each blade.

Here they are:

My favorite method for growing it is in containers, either above ground, or buried in a container with the bottom cut out. A heavy duty, deep nursery pot (18" or more), with no bottom, buried in the ground with just an inch exposed will effectively contain it. Like Bamboo, rhizomes will try to escape over the top, but you can easily spot them and cut them off.

I’ll have to see if I can find a picture of a large stand of this and see what I may be getting myself into. Do you think both grasses are the same, even the one that is more white?

Donn, when you describe sinking the pot "buried in the ground with just an inch exposed" do you mean leave the rim of the put sticking up out of the ground one inch?

Yes. You can hide it with mulch and still see the escaping rhizomes.

Yes...I'd think both the whiter example and the other one are the same. If one of them (probably the whiter one) has a tinge of pink at the edges of the margins, it may be a different cultivar, but it isn't unusual to see different colorations within the same clump of Phalaris.

I once saw a large stand of Phalaris, planted in a teardrop-shaped island in a turnaround driveway. It was the only plant in this ~10' diameter island, and was surrounded by blacktop. It was absolutely stunning, and couldn't run anywhere.