The 4.25" stroker kit is pretty easy to install. Usually just need to take a bit off the oil pickup boss, and you can still use the internal oil pump pickup tube, and don't have the clearance the bottom of the cylinder bores.
On a non-race street type engine the 6-quart Hemi oil pan fits nice and does not hang down below the K-member.
With the TF240 heads and Hydraulic roller cam, I would not expect more than 650 HP. If your looking for 700+ HP, the TF270, larger port intake manifold, and solid roller is likely needed, but that is more of a race setup than street.
With the stock engine block, balance the need for displacement with durability.
The only issue I really have with the 440 source kit, is I wish they offered more piston choices than the ICON pistons.