The benchmark of what is the 'ideal' crappie fishing combination changes from year to year as manufacturers roll out their new products.
I think you're on the right track though by having at least two rods/reels.
1) A 5'6" footer for shooting docks, fishing bridge columns with low clearance, use for fishing on docks/barges around crowds or for poking in dark cracks or crevices. Also good for casting & retrieving small spinners like Beetlespins, Roadrunners, curly tails or a jig -n- bobber combo for when the fish are more active in the spring and fall.
2) A long rod, also called a jigging pole or crappie pole in the 8' to 10' lengths are good for dunking a jig or minnow/bobber combo in shallow, flooded vegetation when the crappie or spawning or have been forced into gnarly places. It's is well suited for vertical fishing during other parts of the crappie calendar year as well, like after the spawn and summer as fish key in on brushpiles or vertical cover like standing timber. In this category you find manufacturers like Pro Angler, B & M, Bass Pro Shop Crappiemaxx and Lew's Wally Marshall products.
As you take note of the time of year you fish and the types of situations you encounter and the tactics you end up using, you may find the need for an additional setup as well.
But both of the aforementioned will take care of most of your angling needs and the cost is relatively cheap to purchase either combo.
Like buying a boat - opinions vary on what is the best - there are lots of good products in the marketplace by reputable manufacturers. It's best to (test drive) a model by fishing with a friend and settling on what is best for you.