Hi Ian, most likely it will be a better for you to sell the Mac, but keep its hard drive (or bring all your data on an external hard drive) and bring that over, and get a new Mac.
Your Mac is a lovely machine, but it will be heavy to ship over.
If it has additional value (sentimental etc) that will bring to another consideration, but in general.. you probably will have a lot of things to bring or ship over anyway.