Add additional memory

I have a G4 power book laptop. For some reason my laptop is running real slow. I was wanting to upgrade my memory. I have 1 gig that came with the laptop. I was wondering if I could add a new 1 gig chip from Kingston. The memory is PC2700 DDR SoDIMM notebook memory. The model # KVR333SO/1GR. Will I have to add 2 new chips from Kingston or can I just add the 1gig memory. I'm not sure how the compatibility of the Kingston memory would be with the memory that came with the laptop with I bought it new from the MAC store. Also thinking about a new hard drive. I'm looking at the Seagate 250 serial ATA. Model # ST90250N1A1.
Thanks

I did a little INTERNET research and found out about the memory. I have 2 512mb chips. I will need to purchase 2 1 gig chips to upgrade. The Kingston memory will work. I also found out that I will need a hard drive that is not serial ATA. I will need to stay with EIDE hard drive. The G4 powerbook will not support a serial ATA drive.