Yes, it's Acer carpinifolium. Hornbeam is Carpinus, hence this is a maple where the leaves resemble Carpinus. I have a cultivar called 'Esveld Select', that is compact and pyramidal, and a straight species. And yes, of course you can grow it as a landscape tree.

I found mine in two different nurseries in the BA but we abound in specialty nurseries.

Yes, chances are it can be found at a west coast nursery, where the vast majority of all US nursery stock is grown.

I think that the species A. carpinifolium was grown at the place I bought it (Sonoma Hort.). The cultivar came from Oregon, no surprise!

Thank you all for responding. I appreciate it.

See also this thread http://forums2.gardenweb.com/discussions/4408027/acer-carpinifolium?n=16

Sara, do you have a photo you can post of 'Esveld Select'?

Not a good one - at this point after 110 degrees over Labor Day, virtually every deciduous tree looks blow-torched. Mercifully I was in Rhode Island enjoying beautiful weather that weekend, but the garden was NOT happy.

I am such a lousy photographer but I will try next spring when it leafs out.

Except maybe for the bonsai aspect species doesn't offer much apart from the amusement/novelty value of having leaves that look like those of common hornbeam. I wouldn't plant it outside of a collection, where there was room for plants "of botanical interest".