The K molds you have is hand pour only. It does not inject well at all.
Dels is nearly identical to a real Senko. They come hand pour or inject. Hard to find used these days. I heard you can prder it through Lurecraft and they can get it pretty fast.
Bears 5.25 is same length as Senko but thinner.
Bears 5" is thick as a Senko but shorter.
I have not tried others.
Here is a comparison pic.