Taylor King builds offers a very interesting option on several of their loveseats and chair-and-a-half units. They can install a heavy duty swivel on the base and they're quite unique and comfortable. I sat in several at Market and like the concept. They don't really do a very good job of showing them on their website, to I thought I'd list the styles you can add this swivel base to:

4001-01
4002-01
1038-023
261-01
733-01
5200-91
9700-01
5032-01
5200-01

Here's photos of a couple done this way at Market:

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