System requirements for iPhoto 8? (and the older versions?)

Hey guys,

So I'm using an old Dual 1.25 GHz PowerPC G4, 1.25GB DDR SDRAM running Tiger 10.4.11 (and I know this is an older computer and older OS, I'd upgrade to Leopard if my computer were physically capable of it, but will probably be getting a newer Powerbook or iMac within the year anyway). Though I had pretty much done a straight upgrade--thereby keeping most of my old apps operable--I'm now trying to upgrade what I can.

Anyway, when I had upgraded from Panther, I still only had the SUPER-old iPhoto 2 (from 2002-2003). Although I know that iPhoto is fairly simple as a photo manipulation program (compared to say Photoshop), I would like to get a newer version (even if I know most of them are bundled with iLife, and--with the exception of iTunes--I really don't use too many of those other programs).

So which version of iPhoto would I be capable of upgrading to? I hesitate to go all the way to iPhoto 8 if it could possibly cause any extra strain on my existing boot drive or RAM (since as far as I'm concerned, I'd rather just switch to even an older version of Photoshop, for the added features).

I just ask because I couldn't really find much about the system requirements online...