I agree in picking a smith first and the finish first. If you want the gun to be blued or hard chromed, then a cast frame is not your first choice as the chance of voids can mess with the metal polish. Other than finish, the Caspian cast frame is excellent (I believe Caspian still claims to never have a frame fail in normal service), and I have a full-house John Harrison gun built on a Caspian frame and slide. John worked with the frame to make sure the gun looked go after hard chroming.
I believe most smiths like to build on Caspian frames and slides, but the Caspian frames are now all cast frames. Colt, Springfield Armory, and Les Baer now offer forged frames. My next build will probably be on a Baer frame and slide as I already have guns built on Caspian, Colt, and SA frames and slides.
BTW, the Fusion parts are made by STI.