Can't help on either questions of a revolve.
Only an odd hint or two in making your own.
It is not that difficult to produce.
The biggest thing is to procure a central pivot.
The last time I made one, I fosicked around in a car salvage yard. Managing to find a stub axile wheel hub.
This became the central pivot for the revolve.
Obtaining 8'x4' 5 ply wood boards, which governed the size of the revolves deck  being 16'.
However larger stardard boards are available as standard off the shelf stock.
The hub was bolted on to a ply base board, which was scewed to the stage deck.
The revolve was made up into 8 wedge segments, like a cut cheese cake.
Knocking up a 3"x5"pine timber frame for each of the segments.
Using 3 fixed castors for each segment, the type fitted with bearings, rather than just a cheap wheel rotating system. [check the side slop movement of the castor.]
Usimg the wheel studs on the hub, made a steel plate to except ech segment.
Fitted 2 castors on a nogging on the inside of the frames outer edge. With one on an inner nogging  at the inner edge of the frames. giving each segment, one at the centre & two on the outside of the revolve. [with the outside two castors, a spacer block was used, the same thickness of the central pivot base board. Between the nogging & the castors. The single castors at the centre, were bolted directly to the noggings. {[this allowed for the hieght of the central pivot mounting board, the inner castors run on] The castors were fixed to run in the direction of the revolving line]
The ply sheets were cut to fit each wedge shaped segment frame, with a 1" over lap on one side, to inter lock the segment plate boards into the next segment frame.
I didn't bother with a plyth for the outer edge of the revolve, as it was set into a faulse stage around the revolve. Which was made in a similar fashion of using sheet size segments.
I ran a cable around the circumference of the revolve wedges, to drive the revolve. The cable went thru pulleys on to wrap on a windless drum. with an improvised counterweighted coffee grinder style  handle to wind it.
It took 2 of us less than two days to produce & were able to cover it with masonite & paint it, also didn'tcostthatmuch.
That was about 10 years a go in the bush & they have used it ever since.
Hope this helps!
[hope this will help?]

We built one for a recent show.  My tech guys (translated to some handy dads) used part of an old desk chair for the pivot point (and it had bearings to help it turn smoothly!).  I've also hit the plumbing aisle at the local hardware store to find things for the pivot.