You’re on the right track to how I think, but Toronto is a bit excessive. If a North American club can demonstrate the capability to self fund their trips to UK or Europe, then I would welcome any club to enter.
Balkan SL rep team could be good, but getting the players together to train might be difficult. A lot easier to have Greece, Serbia and other national rep clubs. More of them too.
As an aside, another option may be to play fixtures featuring teams of different Euro nations, playing at a central venue Magic Style. So you could have say four or five NCL clubs playing the likes of Serbia, Holland, Malta, Czech Republic and Ukraine in say Amsterdam. The destination and festival element may make it an even bigger attraction for players of all sides.