A bit of both.
I'd like to maintain a nice constant tolerance, and I realise it's not that tight a tolerance, but I think I'd struggle to maintain it on my lathe using normal turning. The shorter parts would probably be OK, but trying to hold less than a thou (I'd ideally like to aim for maintaining within 2-3 tenths) on a bit bar at 6 times longer than diameter is likely to be a challenge.
The finish is where things get a bit interesting. IGUS provide lots of information and wear rate charts, for their various compounds. The generic option specifies 0.6Ra (N5-6 or rougher end of ground finishes) finish as being optimum (too smooth and stiction/material transfer becomes a major problem), yet their low friction compound doesn't show any greatly increased wear even up to twice that roughness (in the N6-7 area which is the overlap zone between typical ground and turned finishes). As this will be a oscillating application, they also mention the high spots will wear of the shaft, so a rougher shaft can actually give longer service as it'll wear in. Off course I need to tread the line between wearing in to give good performance, and wearing out so things start rattling!
At the moment, I've found a supplier of reconditioned roller boxes, and although it probably won't work in my CNC lathe (it would stop my turret from fully rotating which could be worked around, however I think it'll hit the enclosure when trying to part off), I'll give it a run on my manual lathe to see how things will work out.
If that works, I think this idea will have enough potential profit to justify a new CNC lathe build designed around gang tooling.