These teams could be :
Bucharest - location : West of Romania - Premiership teams : Steaua Bucharest, Farul Constanta, Dinamo Bucharest, CSM Bucharest
Timisoara - location : East of Romania - Premiership teams : RCM Timisoara, CSM Baia Mare, U Cluj
It's the other way around, in the Eastern part we'd have Steaua, Farul, Dinamo, CSM and in the Western part of Romania Timisoara, Baia Mare, U Cluj.
Would be nice to have such a competition but only as a few weeks summer tournament just like IRB Nations Cup. I don't think it's feasible as a competition round robin type. It's not financially sustainable right now.
However, Romanian Super Liga showed some nice and quality games lately, I think better strategy of Romanian Federation is to develop the internal competition, maybe invite some Ukraine or Moldavian (XV selected from their best players from internal competition). I am saying about Ukr or Mol because the money spent on the transportation will be considerably lesser than going somewhere in Russia or Georgia.