Oddball stroker question

Back at this! I finally picked up the boat, and have been working on it, here is what has gone down, I completely de-rigged the boat, pulled the motors, out drives, and transom assemblies. I found some moisture in the Transom so I replaced it with new Okoume Marine plywood, bonded it to the hull, and glassed it in. I wanted to get the glass work done before the weather went to **** and mostly got it done. Now I am tearing apart the engines, they had both been replaced with 360s sometime in the early 80s. As I suspected both engines were junk. Seawater cooled for 30 years with saltwater... Anyhow, while I have 2 5.9 Magnum cores to build I cant help but wonder if I would be better off finding a couple circa 1990 LA 360 blocks with the Hyd Roller cams and build those instead. What is the consensus? Magnum or LA? If I go Magnum, Stock, EQ heads, The RHS/Indy heads, or Edelbrock? Which heads if I go LA? They will be ported regardless. As for an intake I'm thinking Performer RPM air gap, or a crosswind one. My goal is a 9 to 1 Compression motor that will sing at 5000 RPM for decent stretches of time. I'm thinking a cam with these specs: 264 274 210 220 .512 .512 112°
Seeing as how the 360s lasted for 600 Hours with cast cranks if I go strokers I may just go with the Scat cast ones. I'm hoping for somewhere between 400 and 450 HP. Any thoughts?