I'm sorry for your losses. Building this truck should supply some good shop therapy and be a great tribute to them.
I agree with everyone. Use your stock frame and save a lot of time. I put an S-10 frame under my daughter's '46 International because the old one was rusted to crap. It was a pain to swap, etc.
I put a camaro subframe and rearend under my '52 Chev panel years ago and it was a dream to drive.
Currently, I'm putting an S-10 rearend and a Heidts Mustang 2 frontend under my '48 Chev p/u . I did a lot of searching and comparing prices and picked the frontend up on EBAY for $1,525 including dropped spindles, swaybar, stainless front brake lines and free shipping to anywhere in the lower '48.