I am involved in a similar project. Personally, I would look at something like a 12" Jelco and spend the money on better cartridges and associated gear (like a SweetVinyl SC2 to remove the sound of clicks and pops.)
I would rethink your choice of cartridges. Could a Shure with a 3.5 mil tip really sound better than a Miyajima Zero with a 3 mil even if not exactly the right size? In any case, even my Stanton 500 II sounded better than the cheaper Shure with 78s and there are all kinds of different size stylus available for that.
There are lots of ways to transfer 78s effectively. I would confer with as many people as possible (if you haven't already) before you make expensive commitments.
I would rethink your choice of cartridges. Could a Shure with a 3.5 mil tip really sound better than a Miyajima Zero with a 3 mil even if not exactly the right size? In any case, even my Stanton 500 II sounded better than the cheaper Shure with 78s and there are all kinds of different size stylus available for that.
There are lots of ways to transfer 78s effectively. I would confer with as many people as possible (if you haven't already) before you make expensive commitments.