Borgenson box better?
Something to consider- a Howe racing steering quickner...
http://www.summitracing.com/parts/hre-5225/overview/
I've heard of a few issues with the Borgeson box, threads for the pitman, them being rebuilt and not brand new boxes, etc. I don't have one, so I can't personally comment on some of those issues but there are a few threads on them here and on other boards.
Another option is to add a steering quickner like the Howe Racing unit above and retain the stock steering box. The one I listed is a 1.5:1, so, it would take the stock power steering ratio from 16:1 to 12:1, same as the fast ratio steering arms but without some of the header limitations. Or, you could go with the 2:1 quickner and cut the ratio down to 8:1. No need to "de-power" the box for either of those.
Of course, you'd have to re-do the steering column to put in the quickner. But putting in a couple sections of DD shaft and couplers isn't that bad. From what I understand, the Hotchkis Challenger runs a stock power steering box and a Howe quickner. Or at least it did at one point.
Not a solve-all, but another option out there. Especially since the Boregeson unit isn't exactly a bolt in and go operation either.