I don't think you need 10 32watt floros for 20 clones, they don't take up much space.
depending on the strain you could get away with 8"x8" per plant and add another row and column with that 600w
I don't know cm that well so I'm just going to give you the sizes I would use in that set up for small-medium size plants.
6 plants per row and 6 per column, 8"x8" (20cmx20cm) each, that's 48"x48" (120cm x 120cm) or 4ft by 4ft (1.2m x 1.2m)which would do well under a 600w
You could go a little bigger on the plant spacing if you want bigger plants.
For the clones I would give 4"x4" (10cm x 10cm) space to each, and you could have them 5 per row and 4 per column, so that's 20"x16" (50cm x 40cm)
You could light that up with two to four 42w floros (1500 lumen each / 6000 total with four) which would give you 2700 lumen/sqft (30cm) which would be enough for clones.
Hope I got the metric right