Thanks for all the replies, much good food for thought. And after thinking about it a lot, I've come to the conclusion that I've been overthinking it. The Audio Technica clone of the Technics 1200 with USB out should be sufficient, and I found a place that was selling them for $349 instead of the usual $449, and with a 10% discount that brought it down to $314, or not much more than I'd pay for just a phono preamp. Free shipping too.
The online store only had two left, and now there's only one left at that price.
Link . 10% Discount code is "Mobile 10" or available by email.
DISCLAIMER: not affiliated with lptunes.com and I've never bought from them before. But they seem legit.