i can copy all pkgs to one dir, then run my script. and foreach pkg file, it creates PS3_EXTRA/D000 D001 D002 ect ect. and inside each of these folders, i am able to copy the pkg file and rename it to "DATA000.PKG", extract from pkg and copy ICON0.PNG to PS3_EXTRA/D000 and then rename it to ICON2.PNG, and then copy a template PARAM.SFX and modify it correctly as well. i even made an iso and it works great serving it from netsrv.
FYI To install the pkg from netsvr, you just need to put the pkg in any folder (e.g. /packages or /PKG), mount that folder using ps3netsvr and install the .pkg using ★ Install Package Files
Alternatively you can create an "Install Game" with /PS3_EXTRA and mount it from /GAMES or /GAMEZ via ps3netsvr. The ISO is only necessary if you want to mount the "Install Game" directly from PS3. It can be a single ISO for ntfs or split ISO for FAT32.
TIP: A very easy way to create the PS3_EXTRA folder structure with ps3 tools collection is: Copy the pkg files to /PS3_UPDATE, right click on PS3_UPDATE and select Make PKG. It will execute "Create PS3 EXTRA" and the pkg files will be moved to PS3_EXTRA with a copy of ICON0.PNG as ICON2.PNG and the PARAM.SFX. Also the install flag in the PARAM.SFO is updated.