My experience with spillway fishing is that Crappie won't hold position in current, but they will in any eddy water ( or behind any breakwater object).
The only problem I see with the 1/4oz jig is its fall rate (vs a lighter jig), but that's casting in still waters. In your case that may be your only option ...
... unless you can get above the "deep hole" and let the float take the jig to it.
If you're looking for a 1/4oz jighead that doesn't have a shark size hook in it .... I'd check with the jig makers here on the site. I use a #2 Aberdeen hook in my 1/32oz & 1/16oz jigheads ... custom made by Grousefly ... but there are other jig makers that could probably make you jigheads however you want.