Rankins Dragons and Lawsons dragons are the same animal..there just was some debate on the name in the past. Now they are officially Lawson's dragons.
As for importing them into the US from Europe, the process is the same for any other animal...first you have to find a breeder who has an export license who is willing to ship them to the US. CITES permits may be required as well, not sure...but if I remember correctly most of this will be done on the exporter's side..though they probably charge extra for it, as its not free to get a permit and that CITES permit is one time thing.
I know European dragons have been imported into the US before, but don't remember exactly all the procedures required. You may need to be a accrediting zoo or breeding program to do it.
-----
PHLdyPayne