I think the other fork option loosens the front end a bit, just to fit the guards etc.
I'm probably gonna go for the 53, having rode the cargo around the same size...54ish I think.
Hm, That would seem like a reason for the "tight" fork. The Kojaks pictured look like 35c and fit fine. I think 32c or 28c on wide rims with mudguards would work fine.
My first thought went towards the "small" as well. How tall are you if I might ask?
I'd love some pics of the wider fork. And some tips on sizing. Do I need to size up or down because of the steep angles?
I'll write them a mail.