Steve,
We use the S&W Ukon, to do this sort of conversions with much success, we’ve used it recently on a couple of high profile projects. Unfortunately the Alchemist won’t support this in HD (all it’s inputs are SD, it can upconvert but not cross convert HD). We also have a Teranex box in house, the Ukon is defeniatly better. If you’d like a quote drop me an e-mail at js(at)grsv.com.
Juan