I'm currently using a 21.5" iMac with a 2nd 23" monitor for a dual monitor setup. I was wanting to get a new computer as my iMac is from 2011. I was thinking about getting a retina MacBook Pro and just using it in clamshell mode with 2 external displays. I figured that way I'll still have a laptop if I need it.. Because I have no laptop right now. Any issues with this idea? I'd be using an external mouse and keyboard too.