Galaxy Note 2 shows no sim card after radio flash
Get the ODIN package from here. Then use ODIN to restore to "True" Factory Stock. This will put you back to stock (but will not reset your flash counter). Then from there you can start and use ODIN to root the device again, flash CWM and flash custom ROMs. The modem/radio you linked to should be the radio that you will want to flash if you flash an N7100 ROM. But, as you can see, I would stay away from ROMs that are not for the specific model. the T889 has a couple ROMs based on the stock N7105, but there have been changes (things like the radio) replaced with versions that are for the T889.

I eagerly wait for an AOSP build (specifically CM) for the T889, until then, I am running one based off the N7105 with the Bullet Kernel by cmenard. This kernel has the modules for CIFS support, which I use constantly.