I have the JD2 Model 3 bender. I think you'd be well off to get the 1.75" die, as it is good for bumpers and cages.

I already have that size, this 1.25" die should round out my options nicely.

Consider the radius of the die before you buy. I got the tightest radius possible for the 1.25" die at 3.5". My 1.75" die is a 6.5" radius. If I were to do it over, I'd probably go for a tighter radius on my 1.75" die if one were available.
Regarding the lumber rack, it's going to be awfully hard for me to describe, so you'll just have to watch what's up over the next month.