it kinda depends on what model of PS2 you have...new slimline version = (v12), satin silver = v9, read the stickies if you have troiuble identifying the model of your PS2.
As for the modchip, Matrix Infinity, Crystal, Ghost are very popular choices, Duo2 SE is another popular choice for some of the more aged versions of the unit, i've always enjoyed the reliability of the Messiah 2 personally, but it depends on what chip features you require.
If you just wanna boot backups plain an simple, any of the above would do you proud, maybe even consider the Magic chip for simplicity and cost effectiveness.
the choice is yours my friend, good luck
