Wirh those choices, Elmax, then 440c, 12c27, D2, 5160 probably in that order. I've never used SB1 (that I know of)
440A will be very stain resistant but won't hold an edge as long as 440C. Bur I'm not going to order a custom knife in 440a... while I do own and love a custom I have in 440C.
Polished D2 for me has been darned near stainless. Even in sweaty all year round pocket carry.
Holds an edge well, but a bit harder to sharpen, than other steels on that list. It is much harder to do major thinning or reprofiling. I've done full regrinds if the main bevels on 4 of my D2 blades, and it took "forever" compare to other steels I've done.
I like 5160, it is tougher and less rust aggressive than 01. I own knives in 5160 that have held up well in rough use, but it does patina. I find 01 to be much more stain prone, and rust aggressive than 5160, and even compared to 1095 steels....
Elmax is supposed to be higher abrasion/edge retention, and decent toughness. A great balanced steel, with higher than average edge retention if done well.
I own 12C27, and gave found it to be very easy to sharpen to sticky, scary edges, but the edge retention is not nearky as high as Elmax (whichbis nipping at the heels of other super steels with a focus on edge retention).
My D2 takes more effort, but holds the edge longer in use than my 12C27
Part of this depends on how well the custom maker knows his heat treat.
Also, the design, thickness, thickness behind the edge would all inform my decision.