Is it really necessary to get the models listed in the QVL?
If I want say 6 GB ram but couldn't find the package/model in the list,should I give up or would it be okay to get just some 6GB ram that's not in the list?
I have never used it and never ended in trouble. What I found most important is that the motherboard supports the ram voltage that the memory calls for.
I would just get the 6GB you want. (if you have a LGA1366 system)