'63 brake conversion analysis paralasis

[floormonkey]

I'm stuck in what to do. I ordered some parts with one plan, now I'm considering something else and need some help.

My '63 is about to get a power disc brake upgrade. It's just my around town truck, C10, static drop front with manual airbags in rear, inline 6, nothing crazy. There isn't a small block in it's future.

I picked up a '75 complete crossmember to swap in and ordered CPP CP30106-4 spindles for the 75 crossmember, plus 6 lug rotors.

Now, as I'm getting ready to swap the control arm bushings, I'm thinking I might want to go ahead and do tubular control arms instead.

In that case, I can't figure out if the CPP spindles will work with the 63-70 tubular control arm ( 6370TCA-ULK-B ) or if I'll need to go ahead and swap the crossmember if I want to use those spindles.

Or would it make more sense to use the 63-70 tubular control arms and just get the correct spindle?

I feel like I could probably run the 63-70 tubular control arm and do a ball joint change to use the spindles I have.

Thanks for any help you can give.