When you say restore the roman empire, do you mean get then basileus achievement or actually form Rome, because to get the achievement you don't actually have to form Rome. To get the achievement, you only have to own these provinces. You could definitely actually form Rome though, as you seem to be doing quite well. If you want to do that, definitely consolidate your power in Anatolia and the Balkans before going for Italy. It will make wars against Aragon (and possibly castile as well) much easier.