I know this isn't what you were expecting to hear, but your 2000 with the 5.3 will be much happier with the cats left alone. They are not the restrictive type of a generation before and the 5.3 will become a low rpm dog with them removed. Also, you would want to leave the sensors in place but have the rears shut off through a PCM tune.
If you know someone that went that route and noticed that the truck was changed and not for the better, seems like you already know what's ahead of you if you do choose to remove the cats.
Now, if you were swapping the stock manifolds for long tube headers and finishing the system with some sort of x or h pipe and keeping it true dual with the right diameter of pipe, that's a whole different and better story, but hacking the stock exhaust on your truck to make true duals is not the best way to go.