As far as I now (I don't use modchip) the last firmware version for Matrix Infinity was 1.93
I've been reading a little and it looks like you should look for 3 apps:
November 24, 2006
Firmware V1.93 Released.
Released today V1.93 Firmware for the Infinity Modchip.
New Features and additions:
- Taiwanese V14+ fix
- Firmware 1.93 - 244Kbps
- Dev2Install v1.1 - 152Kbps
- Infinity Manager v1.36 - 140Kbps
I hope it was helpful. The official webpage is closed, but Google is a friend
PlayStation 2 [SCPH-30004 R]: Free McBoot 1.8c + Network Adaptor 80GB HDD
PSP 2004: TA-085v2