Having been involved in mfg. operations, I learned one thing. It's more efficient and economical to build a standard product. I also learned folks wanted custom features, but still expected standard pricing of the basic product. Costs increase and efficiency decreases when additions, and/or deletions enter the equation. Just look at the evolution of the automotive industry. At one time, an option(s) required a special order. As demand for an item increased, it was added as standard and basic product costs increased. Then, options became packages, not single items. And still, one might not get the desired option in a package along with several unwanted items.
I'm continually frustrated by not being able to get exactly what I want. However, I've resigned myself to being frustrated, or just accepting reality. I'd love to have an opening windshield on my R21EC. Opening all the hatches doesn't ventilate that small cabin sufficiently for GA summers. The overhead head hatches open to side instead of fore to aft, limiting airflow. The AC unit works, but not well enough for sunny days with temp in the mid-90 plus range. But, that is what the R21EC is.
I've considered the R23. But, it doesn't have an opening windshield; I'm not sure of the hatches orientation. If I get really serious those factors will affect my decisions. My Rosborough RF-246 had an opening windshield and plenty of other ventilation; it also had a super HVAC unit. I found I liked a lot about the things twin O/B's offered. However, a ten year old boat is a ten year old boat. If not properly maintained, (and maybe even then) O/B's are horrendously expensive to maintain and repair. And, a lot of things on O/B's aren't readily observable, even by a qualified marine surveyor. Of course, a new R23 with a new O/B engine is a different animal. But, O/B systems are really complicated compared to the diesels. The lift/tilt systems alone are an engineering feat.
I've watched Ranger (Fluid Motions) grow over the past eight years that I've been aware of them. IMO,they're best out there at what they do. Check with some of the other mfg.(s) ordering process.