GDRom drive replacement found!

[SWAT]

Yes, it would be ideal. G2 bus is four times faster than G1 bus.
It's good for the HDD, but this bus is slow for memory, 20 times slower than system memory. And only 64 MB. But this is usable for some stuff, as an example of a SPU memory (AICA connected by G2 bus).
I was thinking over some extension board, which would have Ethernet, video/audio decoder, USB host and/or HDD. But I do not have sufficient knowledge to implement it