What chip is the best for a version 9 ps2?

[EVOEvo]

well to them they r happy with it if they want a real mod they can buy it later on when they get the cash i can sell them a used ps2 with the chip install for a price of a new one then if they want a mod and ask me about it i give them some links to installers but if they dont ask about any way of playing w/o swaping then i dont tell them it just gets me more out of a used unit them a unit its self

i had one guy who bought a flip top from me send me the unit to install it lol i told him there was nothing to it but he wanted me to do it so sence he bought the flip top i charged like 10$ more on the lid then what i payed to make money then did it for free but he had to pay shiping there and back on something he could had did his self