Some resin questions

[bryand]

I am trying to decide on the type of resin to standardise on, and my choices look like:

ABS-Like for anything with moving or meshing parts.
Needs IPA
Wide range of colours
Plant-based Low-smell so easier to use indoors (garage & shed both too cold in winter).
Needs IPA
The most limited range of colours
Water washable Easier to wash but you still have a solution-disposal problem.
Wide range of colours

1) Are there other important factors to bear in mind?

I print on an Elegoo Mars 2 Pro, and have an Elegoo Mercury wash/cure unit.
The Mercury doesn't have to be in the same place as the Mars i.e. it could go in the garage

2) Resins are manufactured with a 12-month shelf life.
Which suppliers send you resins with the longest life? (presumably those with the highest sales)

3) Is there any benefit in using UK suppliers other than Amazon Prime? (lower cost may be offset by higher P&P)