You don't need the FDS ROM if you're just planning on running any% or warpless, because the US and JP versions are identical in that case. Minus world ending is different, though
To get the FDS ROM to work, you need the FDS bios ROM as well, which you can find by using Google. After you've found one: In nestopia, go to Machine > External > Disk System > Options. Click Browse and find where you downloaded the FDS ROM, This will now allow you to open ROMs with FDS images.
Effective immediately, any submissions using the SNES9x emulator will not be verified. The SMB1 mod team has concerns about its integrity due to its ability to overclock and remove lag frames, which may not be easily detectable. Additionally, we request that all BizHawk submissions avoid using the S