Quick google search tells me you just have to get the save from your PS3 to your PC (I used a FAT32 formatted USB flash drive), open the save in bruteforce, decrypt it (i.e. just click a button), manually change the region identifier from BLUS-something to BLES-something by right-clicking the save file and choosing the option in the menu, rebuild the save, move it back to your PS3 and you're done.
Doesn't seem too hard. There are youtube tutorials for it if the tool seems confusing. Looks like the only thing you really need to know is the PAL version's region id, which I would imagine is easy to find out on google.
e: But like I said, I'd wait for confirmation that you can just convert the saves from one region to another before going with the PAL version if importing your own data is important to you.