iBook G3 600 Mhz upgrading to Tiger

I am running Panther 10.3.9 with 384 MB of RAM and a 600 MHz powerpc g3 processor. It runs smoothly with everything except streaming video off the internet 😟
I've gotten a copy of Tiger and am going to install it using a friends mac and crossover firewire cable, would this slow down my machine too much? Or maybe speed it up? 🙂 And also, I'm considering buying a 512 MB ram upgrade. Would it be worth it?

http://eshop.macsales.com/item/Other%20World%20Computing/100SO512328L/

So basically I want to know, should I upgrade to Tiger? and would I be able to easily stream video [watch without lag] if I upgraded my ram with a 512 stick?
Thanks for the help in advance