IMO, you are better off going with a 90.
Weight is a real issue on 17' hulls... it isn't about having more power to lift the weight out of the hole, it's about the butt-heavy handling of the boat making it want to plow into the chop, and having the motor well frequently submerge in a following sea. More power doesn't help with those things... moving weight forward can, or going with lighter engines in the first place. The 17' hulls were designed in the era of 2 strokes, when a 90 hp motor weighed 250#... the conventional wisdom is with modern engines 90 hp is ideal for a 17', 115 for a 19', and 135-150 for a 21'.
The Yamaha 115 is the same block as the 90... the extra HP comes at the top of the RPM range where it really isn't very useful in an Arima. The Honda 90 will have similar performance. My personal preference would be the Suzuki 90, which is lighter and geared lower (which lets it turn a bigger prop, which helps improve the Arima handling characteristics). There is no way I'd put a nearly 500# motor (or even a 400# one) on a 17' Arima.
Spend the $$ you save on nicer electronics, or a kicker. The 115 will make the boat slightly faster (from 32-34 mph top end to 34-36). The idea of a bigger engine not working as hard and getting better fuel economy in an Arima doesn't really hold up. In years of following this forum, the best fuel economy numbers I have ever seen on a 17' Arima were with a 90 hp Suzuki (AK Angler's old set up).