Build up existing frame w/ suspension or buy a complete aftermarket frame?

[HellaciousA]

I've got a 70 c10 swb, that has a 67 frame. I am debating about whether to do the following:

1. Clean up and back half the frame with a no limit rear rail kit, add a fatbar, and wide ride, 9 inch rear etc. Cost wise I'm figuring this will be close to $8-$10k depending on options

2. Sell the stock frame as is, and buy the pro 10 frame from no limit. With options I'm sure this will be close to $12-13k if not more.

My end goal is a truck with 6-700 rwhp, and can pull .95 g's on the skidpad (if not better depending on what tires I'm running). Those that have built up a stock framed truck with aftermarket components was that worth it? Or is it worth the extra coin to just buy a completely new frame that is much stiffer and well-engineered.

I've been debating this now for going on 3 months off and on, and keep looking through the numbers. I'm not doing a quick restoration on this truck, so I'm prepared for this to take a few years to complete. I also am not one to cut corners for the sake of time. I want this truck to be reliable and a blast to drive.