What modchip to choose - MagicIII or Messiah2?

[qtip]

I have recently bought a PS2 machine in Norway.
My model is: PAL SCPH-30004R

I have looked into both MagicIII (with clip-kit) & Messiah2.
I have a friend who is willing to install the chip, he has never before installed anything in a PS2, but has experience reparing cellular phones etc.

Which mod-chip would you recommend both regarding functionality and installation?

I basically know that Messiah2 is a better chip, but MagicIII far more easy to install.

Are there any big problems with the MagicIII chip?
Are there som games (backups) that won't work with MagicIII?

Regards
Qtip