You don't say what your budget is.
If buying new, then I would seriously investigate an iMac 27" 5K. This also takes care of monitor. Very nice, very capable.
If considering a new MacPro, I would wait if you can or find one used.
There are lots of older used mac models that will work great. You don't say what type of camera(s)/format/resolution you will be working in, so how to configure your system really depends on that.
See this article by Larry Jordan, getting a little long in tooth but still worth a read… [url=http://]https://larryjordan.com/blog/configure-your-system/[/url]
To see comparisons between various CPU/GPU and model systems I recommend checking out BareFeats as Art does a good job…[url=http://]http://barefeats.com[/url]
You can also see the performance of various models/configurations at Diglloyd Mac Performance Guide… [url=http://]http://macperformanceguide.com/index_topics.html[/url]
Having said all this, most folks expect that many/most/all Macs will be updated SOON, so you might want to wait till later this year early next year.