Usually you see 3 versions on market, all unlocked: UK/Europe version (ROM preloaded with European language sets and ime), Arab version, and Far East version. Except Europe version, other versions may have additional letter/symbols printed on QWERTY keyboard, e.g. the Far East version may have 4 keys printed with additional characters. Those additional printing does not draw any attention, very low profile, they are for specific input methods which unlikely you will ever use, hence you can totally ignore them.
All these versions can be upgraded to All Language ROM, so regardless which one you purchase, a simple, safe, official ROM update will bring it to support all language and input methods RIM ever had. Latest ROM is from RIM website for Indosat, version 746 generic ROM for all 9981 under any carrier, by far the most stable and power efficient ROM for 9981 (I only need to charge the phone every 2.5~3 days with mild usage). Of course the size of OS is bigger than usual one, and you have to remove the redundant language files from Phone Option menu.
Check the phone ROM when you first turn it on: press alt + left-shift + H, read the line below "software bundle", you see something like 220.127.116.11xx or 18.104.22.168xx, those are factory pre-loaded ROM version. If they are 2xx or 3xx, buggy version. If they are 4xx, 5xx, not good on battery life. 7xx is usually ok, 746 will be the best.