Aft, Center, Yanmar...but,
Actually, it kinda depends on which boat I'm driving whether I prefer a cockpit aft or center, but, generally speaking, I like aft because it's a simpler process to the steering gear from the helm. You want to keep the main cabin as close to the center of gravity and center of effort as possible because it pitches less because it's closer to CG. Aft cabins are nice in some respects, but you have to get used to more motion on the ocean while sleeping or whatever aft.Yanmar parts are generally available around the world, but I repowered a 78h30 with a 24hp, Danish-built Bukh 2-cyl diesel which is a commercial lifeboat engine built to run as long as you get fuel to it or to sit up for years without hardly being touched and then crank when you need it most. Support and maintenance along with parts are likewise available around the world.But, that's just me.