You are using 32-bit Windows Vista, and thus 32-bit Java. This means you are unable to run a majority of the 1.6.4 packs due to not being able to assign enough RAM to run them (hence the crashes). Even if you did, you only have 2 GB of RAM, which is the minimum recommended RAM needed to assign to Java for these packs, which is not possible as your system is also using RAM at the same time.
The only 1.6.4 FTB pack that is designed to run on 32-bit systems is FTB Lite 2. See if you can run that pack; if not, please post a new console log to pastebin.com and we will help you get at least that running.
The only long-term "solution" to this for you is to get a new computer with a 64-bit OS and more RAM.