SOTW Columnist, Distinguished SOTW Member
I think there's a good chance you'd end up preferring the TH&C to a VI or a S20.I think the Buescher 400 would be easier to resell later when you're able to get a VI or S20.
I'm not familiar with SML, but own a couple of Buescher tenors and they are very versatile horns, with a great sound. The TH&C has a rep as the best of the Bueschers. That's debateable, but it would certainly be a good choice, and almost certainly will not lose any value if you do decide to sell it in the future.