2017 prices will fall as the 2018's come out. It's costing the dealers money to have 17's sitting on their lot.
I would buy from a dealer with a reputation of helping their customers as well as being able to communicate with the mfg.
Brand is less important than both of you being happy with the floor plan.
What we like in an rv floor plan is having an island bed, sofa and a dinette.
The island bed allows full walk around room to make the bed. We have found that sofas are more comfortable than sitting in dinettes for long periods of time.
Make sure the trailer tires as well as the axle(s) have enough gross weight rating to carry the load. Full real load...not a useless dry weight. If you choose a single axle trailer double check those numbers so your capacities are in line. Lower priced or lightweight rv's sometimes can cheap-out on things that are important.