These are all valid points, since is only sensible to change piston and rods, going all the way to a 416 with the crank is a good plan which makes it easier to hit your target with more cubic inches and less compression ratio.
If you go stroker, you'll need at least the following to hit your target:
416 stroker kit (the one I have is a 10.8:1 CR)
Camshaft with 7.5mm fuel pump lobe (we used 236/248 @.050" and .698"/.706" lift, I would have gone a bit smaller)
LT4 fuel system (pump and injectors) and ZL1 in tank pump.
A SC capable of delivering ~ 12psi boost (I used a Heartbeat 2300)
Good exhaust system (we used ARH LT 2" primaries, 3.5" collector)
Water/Meth injection system.
Dyno plot is below from our 416 setup with 12psi:
Attachment 908300