Please supply drawings, quantities and number of variables, sizes, sizes of sections anything that is available.
If the job is big enough (quantity)to warrant the expense it is usual to design a jig or fixture to hold these components.
It is relativity easy to design a fixture to clamp to the bed of the machine with drilled and tapped holes to allow changes in clamping. Larger companies regularly place these holding fixtures out to specialist contract shops to make for them. There is always a cost.
You have to weight up the cost of making a fixture and calculate how much time it wills ave you in setting up on each component, after you have analysed the cost differentials then you can decide what to do.