Wise move 10.5.6 to 10.5.8?

[Surfrider]

I just update i-Tones, now it's telling me to update Safari 3.1.2 to the newest version to get to the i-Tines store.

But that requites 10.5.8.

Any disadvantages to this?

I forget (old farts disease) how to do this w/out wiping all my crap out, I don't want a clean install I don't think.

Thanks for helping a doddering old fool...