not everyone wants to be a playboater. If the OP had stated that he wants to learn a more play oriented style of kayaking that would be one thing. However he or she has stated that he is more interested in river running. If one has no intention of playing more then the occasional surf session a playboat is not necessary and has more of a potential for discouraging newcomers. The learning curve for boat control is much harder in a playboat then it is in a river runner. Which may lead one to learn a more refined set of boat control skills through persevering during the beginning but it will take them longer and with more frustration along the way. If one also has no interest in becoming a playboater then they also have no need for a boat designed just for playing. Yes a good paddler can take a playboat down most rivers but the OP does not sound like that is his desired intention or paddling goal. Some paddlers just have no interest in playboating which is just fine.
On the other hand there are a number of great river runners out there that will be much easier to learn good technique in while providing a boat that will last the OP longer due to the fact that it is designed more for the paddling style he or she desires to learn.
If I was the OP I would look towards a Remix, Mamba, Burn, Zen, Axiom style of boat. These all provide a sound solid platform from which to learn and grow while providing a boat that he or she's intended style will not out grow within a season.