I’ve had Cat and IPD kits side by side on the bench. If there’s any difference between them it’s in the chemical analysis of the material, they’re identical by measurement. I’d go so far as to say Cat and IPD both source some of those parts from the same supplier.
I've rebuilt many detriot engines. Your engine is very easy and cost efficient to build. IF, and I say IF, you can find a reputable shop to do the rebuild. Don't just take it anywhere. Mechanics these days are terrible. Even if you have to have it towed a couple hundred miles, find a GOOD mechanic. Ask around, ask for recommendations. It will pay off in the long run.