imac 27 retina with fusion drive a good choice?

There's no right answer here.

Most any Mac will do well with image graphics work, though heavier loads and video processing will push you toward a higher-spec system.

How much storage you will need is another factor. Also if you're going to keep the Mac for a while, then more memory, and more disk (or Fusion, or SSD) storage and faster-spec processors are usually better — that'll usually give you more headroom as OS X and application software requirements increase over time.

As for your question, there are reasons why Apple offers different choices here — there's no one right answer. Some folks want a big (cheap, slow) hard disk, some want a (small) fast (and expensive) SSD, and some want to split the difference with a Fusion drive, for instance.

Anti-glare displays work very well where there's glare, but some folks don't like what that finish does for the sharpness and colors that are presented.

A visit the Apple Store and a look at the options might help you. You'll be able to see the anti-glare coating, and discuss your requirements with the Apple folks.

Apple new systems and Apple refurbished systems have good warranties — but check the warranty — I believe it's the same for the Apple new and refurb equipment. If the Mac is acquired from other sources, you'll have to check with the vendor.