Unfortunately the pickings in plastic are pretty slim. I certainly agree about the Revell America. The problem is finding one. (It was only in production for a year or two, as I remember, and it hasn't been reissued often. If you can find one labeled "Civil War Blockader," better grab it. I think it's just the America with a couple of guns added.)
I can only think of a few other plastic kits that could be described as schooners. Pyro, back in the earliest days of styrene, issued two that were inspired by/pirated from wood kits: the fishing schooner Gertrude L. Thebaud (borrowed from Marine Models) and the Revenue Cutter Roger B. Taney (from Model Shipways). Both were nice, if unsophisticated, kits, forming solid bases for serious scale models. Both have been reissued several times in Pyro, Lindberg, and Lifelike boxes (and probably others) under those and other names ( "American Cup Racer" and "Independence War Schooner"). Pyro also made the sail/steam Revenue Cutter Harriet Lane, which was schooner-rigged and later reissued under the name "Civil War Blockade Runner." I occasionally see it in Lindberg boxes.
Aurora used to make a Bluenose; I believe that's the kit currently being sold by Academy. And Pyro used to make an Elsie, in its "dollar series." That one surfaced recently in the gallery over at modelwarships.com.
A long time ago, ITC offered three schooner-rigged yachts, the Atlantic, Waterwitch, and Corsair. And, come to think of it, the old Aurora War-of-1812 privateer Corsair fits the definition. I think the ITC Corsair was reissued by Glencoe some years back - but I'm not sure.
That's the best my tired old brain can do at the moment. There probably are a few others that I've either forgotten or never heard of.
For what little it's worth, I think I'd recommend the Revell America first and the Pyro Thebaud second, with the big proviso that both are awfully hard to find - and probably expensive. This situation bugs me; a schooner is an excellent way to break into sailing ship modeling. Here's hoping that, if the manufacturers ever do get interested in sailing ships again, they'll bring us an up-to-date Gloucester fisherman and/or a revenue cutter.
The better news is that, as was mentioned above, there are some nice wood schooner kits out there - in several levels of difficulty and price. The Model Shipways Phantom, Elsie, and Benjamin W. Latham are particularly nice. And Bluejacket's range has a whole category devoted to schooners.