My thoughts, and a counterpoint to advice to buy used. If you can afford it, you buying new helps you meet some key criteria and lessens the chances that you will get a boat that does not fit you or meet your needs.
You want a modern planing hull short boat. This takes advantage of ease of handling, turning, predictability, and modern outfitting, which allows someone not familiar with what good outfitting is to still achieve a good fit. Think of the importance of fitting your alpine ski boots. Boat fit is no different
Which category boat is best for you.
River running boat - designed to keep you on the surface and handle more vertical river/creek situations
Pros - Easy to handle, predictable, easy to roll
Cons - If you want to play and who doesn't, they are not designed for this. Can you say Eddy flower?
River Running Play boat - Designed to be stable, predictable, easy to handle through class 4 and easy to roll. Will not do as well as the river running boats on more vertical runs, but not an issue for class 3 and most class 4.
Pros - designed specifally to enable an safe stable learning curve for river running, while allowing you to develop your play skills. Design concept is to be predictable for river runners first, and play second. Reverse order of priorities for play specific boats.
These boats are ideal for people to learn to boat in and are used in many paddling schools including RMOC in Salida.
Unless you know you don't want to play in river features, I'd stick with a river running play boat.
Now you're ready to pick the boat. I won't comment on boats I have not paddled, but I have paddled the Jackson Fun Series, Pyrhana I series, and WaveSport EZ. I don't think Dagger has a good contender in this category. I'd also consider an EZG as I know of several people who like them.
Bottom line - The Jackson Fun of the appropriate size for you and the EZG are a choices you can't go too far wrong with. These boats are designed to be stable, predictable, easy to handle, easy to roll, and they handle big water and class 4 no problem. They will suppport your play skill development quite well.
There is an advantage to getting the 2005 Jackson's over the 2004's. The backband is improved and the hippads fit most people more comfortably. Whichever boat you get, I recommend getting the new Jackson Happy Seat. This will improve the fit and hence boat control in any boat, and will make you more comfortable as well.
Hopefully this gives you more of basis for choice, or at least opens up some additional things for you to question. Hope you find this helpful and good luck.