We want to get a bunch of iMacs for video editing, Photoshop, After Effects, etc. and would love to go beyond 16GB ram and have better graphics cards, etc. though the 27-inchers are just a bit too large for the space they will be used in. 1. Anyone have any thoughts on using the maxed out 21.5 iMacs for Premiere, After Effects, Photoshop? 2. Compared with the maxed out 27-incher at a comparable 16GB of ram is there a significant performance difference between the models? Thanks.