I took a machine shop course and graduated,so I spent a lot of time on full-sized lathes,and to be honest it would take a couple tips to be comfortable installing a tip on one.
There is a HUGE difference between a Hightower chuck for example,and a D1-4 3-jaw,so you gotta start making collets immediately,then fit the back of the spindle for another chuck,etc.
Huge difference in torque too.
Same goes for sanding a shaft on one. I'm sure we've all had sandpaper or a rag snatched out of our hands on typical sanding lathes. That same thing on a full-sized lathe could be catastrophic in my mind.
Now,as far as cutting screws,tapers,and making parts I'm all over it
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If someone was going to bankroll me like you describe,the 40" version of the Grizzly 4003G is what I'd be looking at awful hard,even without a readout.
If the funds were there,the 40" machine with readout and full CNC capability from Micro-Kinetics is AWFUL strong.
If the funds were unlimited,I gotta go with Haas.
And that's just the lathe,the mill is a whole other conversation.
I still do tips on my old Enco mini,and have a small headstock Deluxe plus an old Chinese wood lathe I use for general sanding. Tommy D.