Mod/Game backup help

[WookieWill]

I am installing a mod chip for my friends ps2(I have a gamecube, I know, I know)
He has ver4 ps2

1)Will a Messiah or a Magic2 work with this version?
2)Which modchip do you recommend?
3)Which store do you recommend?
4)I read in another post a user wanted to identify his bios, I thought bios was irrelevant when modding your ps2?
5)Neither of us have a dvd burner, how many games are on dvd media - 10% of games or 90%?
6)When I play backup games on my pc, 99% of the time I need to download a patch/fix for the game, do you normally download patches/fixes for ps2 games too, or do you burn the games straight?

Sorry for all the questions, but you guys give really good answers in these forums!!