Hi,
Yeah, you can do get arabic without rooting your phone, in fact, its harder to get arabic if you root your phone and use custom roms as how i experience it because the original files are modified which making patching them with generic arabic patches found on the net to not working.
Anyway, my phone bought in Singapore originally comes with a V10a firmware, has full arabic support (no arabic menus though) with no problems. But the small problem for you is that, it comes with my operator's custom apps and boot screen, if you can tolerate that, everything else is the same.
From this page, you can see a list of stock roms from various countries..
[FIRMWARE]LG Optimus 2x P990 Original ROM's[DOWNLOAD] - xda-developers
Mine is SINGTEL SINGAPORE
or you can try using various V10a roms, which i suspect all has arabic support. I am not sure whether the new SINGTEL V10b update still has arabic because im now using Modaco custom roms, which has arabic but the letters are not connected.
If you are hesitant of using custom operator stock firmware, i would like you to try the section called INDIA, SINGAPORE, VIET NAM, THAILAND firmware. I don't guarantee that it has arabic support, but its worth the try if you want generic stock firmware.
This guy also posted on xda-developers on his firmware able to support arabic, and has the same V10a version, although not sure from which region, but you need to root your phone to use the CWM backup of his phone.
Rom full Arabic -Farsi (20-4-2011 Updated) - xda-developers
Hope the info above helps.
Cheers.
