Question on Jap PS2 (scph30000) and MODChip

[acx23]

Hi,

I have bought a USBMOD for my Japanese PS2 (I have not solder it yet... got it in www.modchip.com). Then later I've heard that USBMOD don't work on my model, SCPH-30000. Is it true?
And I've also heard that Jap PS2 with USBMod does not require a booting with a GameShark for it to play PS2 backups. True?

Also, should I get a internal mod instead? I got a USBMod cuz I've heard that it is better than the internal ones.

Thanks for any info.