well my bet on the fan-controller-less fan system is a success
the sunbeamtech unit was a perfect match

i got the power unit for the fans today, and then had a dry run with the fans running at full, and the noise is almost non-existing.
plus the power controller was 4 GBP ( ~7 USD )

the fan power unit in its packaging :


it comes with some 2sided glue pad to mount it in the case.

my little experiment :


it was a good decision

SECTORIX.