Here are ISO batch tools that permit to fully created your personalised ISO disc.
It's the easy way I found to do it. You will find multiple package templates that let you install associated files.
Current beta state
PS3_ISO_BATCHb0.6 by 0_obeWAN
- Create/add Mods packages to ISO disc...
 PSN icon ===>>from PNG picture
 XMB wave ===>> from lines.qrc
 Coldboot ===>>from coldboot.raf file
 Gameboot ===>>from custom_render_plugin.rco file
 Theme ===>>from theme.p3t
 video ===>> from video.MP4
 Mod Games ===>>from NPDRM and NO NPDRM
 HB coming... ===>>Soon
 Add manually ===>>from an existing package
- Build collection ISO disc
[ b ] Build ISO disc
- (Optional) PS3 network connection
[ i ] Define PS3 IP address
[p] Upload package on PS3
[r] Refresh and reboot PS3
[d] Upload ISO disc on PS3