It is hard to tell at this point because Reactor is still a sketch and I (Akka tech lead) do not have insight into where it will go. It will be interesting to see if Reactor becomes a competitor to Akka, we are looking forward to that.
As far as I can see, from your requirements list Reactor is missing resilience (i.e. what supervision gives you in Akka) and location transparency (i.e. referring to active entities in a fashion which lets you abstract over local or remote messaging; which is what you imply by “distributed”). For “modular” I do not know enough about Reactor, in particular how you can look up active components and manage them.
If you start a real project now and need something which satisfies your first sentence, then I don’t think it would be controversial to recommend Akka at this point (as Jon also noted). Feel free to ask more concrete questions on SO or on the akka-user mailing list.