How come your limiting the BB to a stock stroke 400? Is it for a cu in limited class? I’m guessing a stroker BB isn’t anymore expensive than a stroker SB. If you’re willing to spend the $$$ on the SB why not the BB? For the hp you’ll need a 4.25” arm in a 400 block will get you there easier.
For that level of HP a BB (stroker or not) would probably be happier/easier, but I have no doubt either combo could hit the number