[Lil' Lavery]

I think your endeavor is a noble one, and I certainly shall not hinder it, and I will offer what help I can give.
But before a regional, I think you should start teams in Germany, and the rest of Europe and start an off-season competition. The off-season can give you a smaller idea of what the work that goes into a regional is, and it can also show some indication of how many teams would be interested in coming to Europe from the US. The biggest problem with depending on US involvement would be rules. After 9/11, many counties either made stricter rules about long distance, particularly out of country, field trips, or even out-right banned them. Some of these have been lifted in the years after the tragedy, but many have not. So many teams would not even have the option of coming. And few that did attend would attend in full force. I know how much a trip to Europe costs, and it is no small fee.
So, in short, build a local support base and try not to depend on out of country travel to support your regional. Getting area teams is your first priority.