I need a new Mac for some specific OSX requirements that I need 1% of the time but for the rest of the time I need Ubuntu, I usually I stick to the LTS releases. I am open to the Mac mini, Macbook air, Macbook Retina, iMac, whichever is most likely to give me the least amount of frustration in terms of hardware compatibility. I'm not concerned about cost or any other factor. I want to run Ubuntu on bare metal, not within a VM. Any advice?