I would put back Ebony (maybe naming something else like Eddie) and base him off on Darwyn Cooke's version of the character.
I would just leave his name as Ebony. Otherwise, what's the point of including the character? You don't have to call him Ebony, though, as Darwyn Cooke had The Spirit refer to Ebony as "Eb".
But me, i'd go all-out Eisner Ebony. In reading a bunch of Eisner stories with Ebony in it(Young Dr. Ebony is great. If you can find it, i suggest tracking down issue 7 of the Warren B&W magazine: the All Ebony issue. Great stuff.), Ebony is probably the coolest character in the Spirit universe and the most heartfelt. He's funny and compassionate and dedicated and truly cares for Denny Colt. The Spirit can't get married without Ebony's permission. When the Spirit gets kidnapped, Ebony's prepared to kick some ass and chew bubblegum, whereupon he finds that he's all out of gum.
As much as i loved Cooke's take, i felt that he ignored alot of the things that made Ebony great in Eisner's stories. Sure he might be portrayed a tad insensitive, but i think it adds a bit of charm to the character as well. In Cooke's stories, Ebony is just a cool talking kid. Eisner's character is that awesome kid with the big imagination.
If i did a Spirit film, i'm not sure what it would be about, but all i know is that P'Gell, Silk Satin and even Sammy would be in it. it would probably be live action, though i'm tempted to make it CGI instead just so i can throw in Sammy EXACTLY the way he looks in Eisner's stories. He's so funny looking.
I'd probably go a bit "James Bond" with it, having The Octopus being the behind the scenes villain whose pulling the strings for something bigger, much like Blofeld. Mr. Carrion would probably be the main villain though. As i said, the women would be P'Gell and Silk Satin, as i think The Spirit has the best chemistry with them, and the stories with Silk just kick all kinds of ass. Ellen would be there too, of course.
and it would be kind of timeless, kinda like Batman: The Animated Series. Making it look and feel like the 40's, only modern invokes an atmosphere all in itself. The film would be colorful as well. I don't care what Eisner or Miller says: The Spirit in color is much better than the black & white versions. It would be fun, but serious. It would have an epic chase on railroad tracks, in the rain, during a storm. That's really all i can think of at the moment. Maybe when i come up with more, i'll post it.
And if i had to, for another film i'd do a straight adaptation of Cooke's take on "Sand Sarif", which, in my opinion, trumps Eisner's. It was probably one of the best comics i've ever read and packed a more emotional kick than Eisner's did. But that's just me.