Hot Rods Model A steering F1 or F100?

I need a steering set up for my model A. Is an F1 box the same as 2nd gen F100 trucks? There is a '55 ford truck box available and I'm unsure of it's size and worthyess. What about the vega boxes?
My A is stock style with flathead and drop front axle. No z or slam. Thanks.

 

The '53-56 box is a little larger than the earlier F1 box, but has been used with success since 1953.

 

The stock Model A Gemmer box works pretty well. Here's a link to a tech post I did awhile back:

http://www.jalopyjournal.com/forum/showthread.php?t=199148