With new iMac's supposedly on the way I think it's a good time to look at replacing my 24" iMac. I'm looking at the current iMac's to give me some idea what my options will be on the new models. I think I will just go with the base 27" model with custom storage, but I'm not to sure what drive option to go with. I have about 250gb in just my iTunes library so I need a large drive, but the 512gb SSD is out of my price range. So what would be the better option to go with and are there any pitfalls I should be aware of? A: Fusion Drive or B: Smaller SSD with an external drive?