my 16GB RAM helps me in only two scenarios:
1) Photo editing: using some software eats up 8GB in a heartbeat, especially if I'm running more than one thing. This is photoshop editing panoramic levels...if you're not doing that, then this does not apply to you
2) Parallels: This allows me to actually game very well on Windows 8 running parallels. You won't need that for windows XP, but since my work requires Windows 8.1, I'm stuck with it. If you don't plan on ever running windows, you won't need it...drop to 8GB
I can only see the CPU affecting your video editing, and I don't think you need a high end...a low end will really do just fine. If you edit tons of videos every day, you can save some time. if it's even just 1 video a day, I don't think it will be worth it. It is a question of what your time is worth.
Other things to consider, if you game on at retina 13", the retina will hurt it at full resolution. Selecting a native resolution eats up the most power on a GPU. If you scale down to what a normal resolution screen would have, your game would look better on the native normal resolution computer vs a retina. I can't give you side by side experience, but that has been the trend in the past. Someone else could probably elaborate on this.
UBS28 mentioned getting an older computer...I think he's right with a guess at what you want. On older systems, you can upgrade the ram yourself, not with new systems. I would seriously look into that. My macbook and iMac really holds their usefulness much longer than Windows computers. I have a 2007 iMac running as a server. My late 2011 SD Macbook Pro still rocks on current games.
One more note: once you go SSD, you probably won't ever want to go back...makes built in SSDs suck when they cost an arm and a leg.
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Thank you everyone, this is my first Mac so coming from windows you don't know exactly what you need when its a different OS and obvious needs different resources, I did not mean to upset anyone.
So it looks like my best option is to go 2.6/8gb/256 and obviously apple care without a question. How long would you see this lasting me ?
And does the 2.6 upgrade making 100Mhz in the GPU really have a noticeable difference ?
the GPU depends on the build of the card, reference this website to get an idea:
http://www.notebookcheck.net/Mobile-Graphics-Cards-Benchmark-List.844.0.html