take a look at trials bike forks, gusset do a few, and you can still find the steel onza straight ones on ebay every now and then. gusset ones are heavy tho : (
have you checked out the new simworks fun bars? rise, backsweep, steel, they got it all!
I had thought about trials forks, but after riding the Salsa fork on my Kona I don't want to go back to anything crazy stiff! Such comf. Also I'd still have to get it modified with rack mounts and shit.
Yup, older Raven fork. 403 a-c, 54 offset.
Really nicely constructed, hope it suits the bike. My last option before custom.