Depends on your application... is this in a truck you do any towing with at all? Do you plan to lock this up in 3rd at WOT?

PI makes excellent converter. I'd go with them over a Yank in an all out application. If you are planning a built 6.0, cam, and nitrous... I'd look for a stall around 2600-2800rpms. PI's stall higher so I'd consider their 2600rpm for your truck. The weight will make it stall higher, then the big setup of torque from the 6.0 will also THEN that nitrous hit.

Go dual pattern on the cam. 224/230 or so. More exhaust duration for nitrous/turbo/blower is good idea. Helps in scavenging from what I remember. .595 is a TON of lift, excessive IMO. I'd drop to ~.540-.570 tops. Springs will have to be replaced often if you run that much lift you are talking about.

Are you trying to build something that can be driven daily or what?