You can see in these kits cast and forged cranks, and different rods (I vs H), and different pistons.
Forged cranks are generally stronger than cast cranks. Stock Mopar cranks are petty strong. Since these look like Eagle PN's and some Eagle cast cranks have been problematic, I'd chose the forged crank.
I beams are generally OK for street use. (H-beams are shown in all of the pix.)
The H-beam kits show a lower compression piston (that wold be more suitable for typical street use). I don't see why you could not get a kit with the lower compression pistons along with the I-beams; to me, that would be a decent street package. But the price range is under $400 difference form cheapest to priciest.
The number of cc's listed is for the volume in the head chambers, and this does not vary from one kit to another per the above link, since they all offer the same piston. The chamber volume varies with the heads (and how you may modify them); your stock 318 heads are around 68 cc for example. If you put on larger 360 heads (which you really would need to do), then the chambers are larger, around 73 cc's.
The size of the chambers works with the pistons and bore+stoke to determine static compression ratio. The compression ratios listed are fairly high; that would be OK for a large cam (high RPM, drag race) but might not be the best for other heads or for a small cam that would be more suitable for typical cruising.
That is the harder part: getting the heads, pistons, stoke, etc. to work together as a package. That is the reason for you to ID what your engine use is going to be for: cruise, pure race, or what?
I see you have answered the question; sorry I missed that. A strong cruiser. For most folks, IMHO that tends to emphasize a wide torque band and less peak HP. A stroker will do that, or any small block that is is not over-cammed for pure racing.
