I'm a graphic designer as well, working mostly in Adobe Illustrator/Photoshop (I might do some retouch work, but mostly design work)/InDesign, occasionally in Sketch and coding in Sublime Text. I'll be working in Lightroom for mostly going thru photos taken with DSLR but not heavy image editing.
I too am considering a 27" iMac 5K, but can't decide between i5 or i7.... Currently I am using Mac mini (Late 2012, 2.3 GHz Intel Core i7) and MacBook Air (2013, 1.7 GHz Core i7). I plan on going with 512GB internal SSD (with external drives for archived jobs and media) and 64GB RAM from OWC.
My question is, will I be completely happy with i5? The cost for i7 upgrade is well within my budget, and if it boosts my productivity then I'm all in. But I'm a little worried about the i7 fan noise issue, which I sometimes have with my i7 Mac mini and MacBook Air. Does the fan kick in that easily for i7 iMac if I'm working in Adobe Creative Cloud apps?
Thanks in advance!