As we have said before:
SENG is half prog half managment
COMP SCI is half prog half whatever you want (could be more prog)
COMP ENG is half prog half elec
In terms of the best place for SENG, I would have to say UNSW. After researching it for open day, and talking to friends at USyd, the USyd SENG course is silly, not a real programming course, not a real Engineering course. The UNSW program lets you be a hardcore programmer if you want, an IT egghead if you want and athough it is not a "real" engineering course, it is at least closer.
But as sunny said it is up to you. As a 2nd year SENG student I am more than happy to answer all your questions about UNSW SENG. Also, be sure to visit the website:
www.cse.unsw.edu.au
and specifically the website in my sig.