Hi,
Thanks, I didn't see the S8550-6Q2C. If it had 8x QSFP28, it would be a good option.
In FS.com, my attention was also for the S5850-24XMG for the RJ45 : Switch Ethernet L3 à 24 Ports, 24x 10GBASE-T/Multi-Gigabit et 2x QSFP28 100Gb, Support MLAG, S5850-24XMG - FS France
A bit power hungry...