Dividing Dobrudja is a very sensible thing to do, since it was divided for most of its history! Not sure why I've never seen that done in EU3 until now. The (transliterated) Bulgarian version of the name is identical to the English one -> Dobrudja. The Romanian name for it is Dobrogea. It seems like whenever a region of Romania does have a name in English, it's based on foreign names and not on Romanian ones, although it makes sense in this case since this region name is obviously of Slavic origin. But let's not go off-topic.
Anyway, I can't really see Romania on that map (I can just see the northernmost tip), so I'm not sure how you have it divided, and how far you want to go with the division. If you tell me in how many provinces you would like to have it split, I'll definitely think of something right away.
The historical regions are as follows:
Muntenia, Oltenia, Dobrogea (Wallachia)
Banat, Crisana, Maramures, Transylvania (Transylvania)
Moldova, Basarabia, Bugeac, Bucovina (Moldova)
But you can go much further with the divisions - it just depends on what you have in mind!
As for alternative names:
Dobrogea - Dobrudja - Dobruja
Basarabia - Bessarabia
Bugeac - Budjak
Bucovina - Bukovine - Bukovina
Transylvania - Transilvania - Siebenbürgen - Ardeal - Erdely
Here's a map of the regions that might help you:
Attention though, only half of the Banat and Maramures regions are included in that map. It's a map of the Romanian historical regions, as in - places where Romanians live. The Banat was traditionally a place of confluence of 3 cultures, Romanian, Serbian and Hungarian (in this order of size, the Romanian Banat made up about 55% of it, the Serbian part about 35% of it, and the Hungarian one about 10%), therefore the parts of the Banat where Serbians and Hungarians lived are not included as part of the region in that map. Also, disregard the little thing in the south-east called "Cadrilater" ("Quadrilateral" being the English name), it was just an anomaly of history and certainly doesn't deserve to be separated from the Bulgarian Silistra, as it has always been an integral part of it.
Hope this helps.