So, the same setup minus Hexxit using minecraft 1.6.2 Only used 1.8 GB of RAM. With this and other tests i think that the issue is with Hexxit. This or the newer update has managed to fix minecraft and the Java related memory issues. In which case i can not wait for the 1.6 Technic platform updates... If anyone else is not having the same issues with the same set up let me know, i have already attempted x64, x32 and SDK JRE versions of Java.
**Edit** I am also using "Increase Perm Gen Size" and 11G in the Hexxit Launcher