Ok, so you want to upgrade you G5 Powermac to cater for the more advanced and professional programs, such as Aperture and Final Cut Pro. Well, there are many different brands providing upgrade parts for Macs, but in experience, I believe it is always better to stick with Apple as much as possible when upgrading.
This webpage should be helpful when upgradng RAM, which is vital when running these programs. Just select the exact model of you G5 and choose how much RAM you want. However to run these programs smoothly then I can only advice the following for a smooth ride:
2GB of RAM
One of the following graphics cards: ATI Radeon X800 XT Mac Edition; ATI Radeon 9800 XT or 9800 Pro; NVIDIA GeForce 6800 Ultra DDL or 6800 GT DDL; NVIDIA GeForce 7800 GT; NVIDIA Quadro FX 4500
I hope this helped
i need some help,to up the specs on my G5 p mac , for aperture ,
final cut pro, also to give it a bit of grunt , i would be greatfull .
mac osx tiger 10.4.6, kernel version darwin8.6.o.graphics card ,
geforce fx 5200. gumboots