You have space for 3 dedicated TT’s, wow!
My friend has room for only 1, and many 78’s as well as mostly 33’s.
for others: Single Table/Arm solutions I have had experience with are:
My Thorens TD124 with 4 speeds, SME 3009II with changable headshells, each appropriate stylus type. Wonderful combo, but SME arm: no easy height adjustment if needed for cartridges with different heights. All could be ’shimmed’ to the same height I suppose. I was just single latest Shure MM in those days.
The Thorens needs a very stable setup, it’s massive platter and bearing design are succeptible to vertical vibration, bad match for my flimsy wood floor
this shows the SME 3009, custom plinth takes second arm
https://www.usaudiomart.com/details/649770090-thorens-td124-sme-3009/
this more compact for single arm, new blank armboard.
I wonder/suspect that Acos Lustre GST-801 would fit, an awesome removable headshell and VTA on the Fly setup. I want someone to have this baby!
.
My friends Technics SP-15 3 speeds, with BP-500 Base with VTA on the Fly, and either 1 curved arm with removable headshell and multiple headshells (his choice), or several easily exchangeable arms with pre-mounted cartridges, including the straight arm with fixed cartridge. The arm changes as easily or easier than a headshell.
Changing height couldn’t be easier, and very precise mechanism. I just installed one for him.
Arm Base and Two Arms (sold, good pics, none active on hifishark now)
SP-15 in Technics plinth, different tonearm. You simply change the round insert for your chosen arm (up to 10.5")