I'm thinking a fully loaded iMac 2.8GHz Quad-Core i7. I want 8 GB SDRAM and understand I'm better off buying that and installing it myself from a 3rd party. Question: How do I buy it & which configuration is best, I see it is offered as 4x2GB($200.) or 2x4GB($600.) from Apple. Whats with that? Also, will installing an aftermarket ram in any way affect future downloads or hardware, eg. will the computer know it has 8GB, will that figure show up in the computer specs? I've had problems in the past with using 3rd party components. Recommendations as to where to buy the ram and which type? Or, I'm I safest to stay with the Apple Ram(and which one)?