I have to go with the 440 -

Even though big blocks period are getting crazy, you can still find 440 pieces parts around pretty easy.
Heck, I'm lucky enough to say I've had a few 440's ( only this one in a good car though ) and the one thing
I can say is they have always been stout with little mods.
Set it and forget it 440. If you like the garage and have deep pockets go Hemi. ( not that I have Hemi experience but heard they could be finiky )