I've owned an Arima SeaHunter (15') for four years now and overall I love it. Seems that most people that own Arima's love them. They are absolutely great for the Puget Sound. Extremely functional. Sure, they will beat you to death in choppy water, but the boats are extremely stable because of their hull design. Like everything, you have to take the bad with the good. And I think the good far outweighs the bad with Arimas.
If I were buying my next Arima, knowing what I know now:
I think the 17' is the ultimate size for the Arima design. Still small enough to easily handle alone, yet large enough to fish three comfortably. IMO the larger Arimas are nice but if you are looking for a larger boat that probably means you are looking to go in bigger water and if that is the case, you should probably go for a different hull design.
Skip tower with full curtains. You can stand under it and still be out of the elements. Best way to go. Take the curtains off in the summer. Great combination.
The largest horsepower rated for the boat. These boats do not plane easily and if you add a bunch of gear or people, the extra horsepower is needed. Sure you can get by with less horsepower, but you don't want to.
Just my $0.02. Enjoy the looking!