Laptops: memory and harddrives

Hello everyone. I just got my Laptop on Friday. I know that this forum is full of very knowledgeable people so I have a couple of questions regarding Laptop components and overall performance. Firstly, I am going to get more RAM. Right now I have 256 MB RAM (two 128 MB SODIMMs). One of these is clearly marked CL3. The other I am not yet sure. I would like to replace one of the 128's with a 512 MB SODIMM. The only catch is that the only 512 MB SODIMMs I have found are CL3. I could get a pair of 256 MB SODIMMs that are CL2, and replace both of the current SODIMMs. So the question is which is better in the long run: a total of 512 MB of RAM at CL2, or moving towards 1024 MB of RAM at CL3. I am currently running Reaktor 3.0, Spektral Delay, Pro52, etc., but I will be getting Kontakt and ABSynth for PC as soon as possible. I'll save the Harddrive questions for a little later.
Thanks, Marc