Can't help you with the id. Echies can be so difficult to id:). I would say Gibbifloras can get the size of a big dinner plate. Is yours kept inside? The ideal look for echies is a tight rosette. If getting enough light they should be compact. Also when recieving enough light most will color up real nicely. There should be no spaces in between the leaves. As they age the tight rosette will keep growing and lower leaves will dry up and drop off. The Echeveria will start growing what looks like a gooseneck. This is when I usually cut mine. I like them low and compact.

Here's an echie that has a gooseneck. They can get real long if not cut. It's all up to your esthetic. There are some people that like the gooseneck look:).

Maybe E. shaviana?

I agree with Rina on the ID.

These ruffled varieties get huge. 12 inches across, or larger, when fully grown.