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[BananaRepublic]

Im updating my work computer to an iMac

my personal computer is a Macbook Pro, which I run Adobe CC from and whatever other photography related stuff, non professional/hobbyist. I want to combine everything into this new iMac. I work from home in administration and mainly use Excel, Gmail dropbox etc.

Naturally I would and currently do keep all the photo files including LR/PS catalogues on external separate SSD.

My questions are around spec given that I want to combine the two units into one and still be capable of comfortably running the photo software, for the next 3/4 or more years.

1) Processor i5 or i7, my current personal has an i7 seven so I sorta have that answer.
2) 1TB ATA Drive or 1TB Fusion Drive, Im also considering resale value when looking at this.
3) 4k display or not

What I have: Mac Pro 15 inch, 2.7 GHz i7, 8GB 1600 DDR3, Graphics, Intel HD 4000 1536 MB.
Work computer is a Mac Air, 1.7 Ghz i7 and the same Memory and storage and it runs the work stuff fine so thats ok the basic iMac could replace that but just wondering about the photography side