I've never ridden the custom, but I have an F. Mechanically they seem nearly identical, but I think handling will be sportier on the F. It does handle very well to be sure, although the original suspension might need work if it's OEM. Dual disk on the front is almost on par with modern bikes. To be honest I was only looking at F's, not interested in K or C.
I would not bother with pods either, these carbs have idle, main and secondary main jets, a non-adjustable (or hardly adjustable) needle, and are CV carbs. They work really well with the airbox.
Valves are shim-over-bucket style, takes an inexpensive tool to grab the shims and there's 16 of them. Fortunately it also means they need less adjustment.
Nice bikes, good luck whichever way you go brother.