I have had pods built for 2 boats. First was my 24 Wellcraft Coastal, and that was a full width step up pod. It didn't follow the hull flush instead stepped up from the transom. Was a really nice job, however the design resulted in difficulties trimming down and porpoising. The only solution was to install a dolfin on my outboard, which immediately fixed the problem. Second boat is a Grady White 265 Express, and for this one I worked with Breakers in Port Alberni to line up their local fabricator. He did a custom job, which included closing in my drop down transom gate to create more storage and a tackle station along the stern where the former fold down gate was previously. Super nice job, with amazing functionality.
The other design consideration was I went with a full hull extension. That created more floatation and lift for the engines, and eliminated any issues with trim and porpoising. I went down the full extension route based not only on what I learned from my first experience, but also after checking in with other guides who had extensions built. Consensus was hull extensions are the way to go. My experience thus far after a full guiding seasons with over 100 guiding days is the performance, stability and function of a hull extension is in a word, amazing.
My build was $7.500, but thinking it was considerably more than most given the additional custom work to construct a close in for the motor well area, with custom doors and a tackle station area. Hope that helps in your design planning. Post a few pics once its done.