naw you definitely do not want the asian version dude.
US is my preferance but as there are no options to getting it repaired *should* it die-- its a little more risky. Ive personally been through 4 US version carts and just dont want to deal with that anymore.
JP version is official and the price I quoted you (300ish) is, as mentioned at cost. Wish it could be cheaper, for myself even but thats the way it is. EMS 2 ways to Japan plus service charges make it pricey.
But considering a motherboard set up can be had for about 100.00 that makes a Japanese full setup, with a brand new battery and piece of mind for about 400.00. Not bad.
In either case... a US or Japanese cart is going to run you some bank... factor in the whole battery situation too which might need to be taken care of depending on the status of whatever you find.
Thanks for the heads up though-- I wont worry about holding onto it for you, but feel free to PM if you can round the money up.