Hi Laurent,
Sounds good...I would suggest waiting until we release the bi monthly rollup patch for 10.2.3 ( Spectrum_10.02.03.BMP_10.2.301) as it contains all of the fixes from the current 10.2.3 PTF patches. It is due out soon.
Once that's released open a support case to obtain it. When you are ready to install, on each install I would upgrade to 10.2.3, stop processd, install the Spectrum_10.02.03.BMP_10.2.301 patch, and then start processd and your SpectroSERVER/OC.
Cheers!
Jay