Wow.. when you said DIY, you really meant it!
A few things I might throw out there. If you are going to cure your rock in the tank, you can skip the dead shrimp. I would suggest maybe just adding some of your clean up crew, and feed lightly (either pellet/flake or frozen) every couple of days. That should also kick start the biologic cycle.
In the size of tank you are looking at, probably only one candy cane pistol shrimp, as they tunnel long and far. Plus, hawkfish are predators of inverts, so it might not mix well with your plans of the pistol and harlequins.
And lastly, most conchs I think either get really big or are predators, with the notable exceptions of fighting/Tonga conchs.
Just my 2 cents ... but I must say, you are really planning this out, which is the exact way to do it!
-James