pls confirm-8 wired mod only for selected model?

[trustno_1]

hi ppl, pls advice. want to play DVD backup games badly. went to the shop to install an internal chip (currently USB mod/GS2/US NTSC/SCPH35001) but said only Japanese version (PAL) capable of doing it. did not get the name of the mod chip, just found out it's 8 wire type. is this true or do i have to sell my US PS2 for a Japanese one (which i have to top up about half the price of a brand new PS2)? thanks.