Are you back in town now?
24v cover will work; case needs to be swapped.
Not sure I agree that a stock 215 will get you to 600. Keep in mind they are core pumps so they may need work.
A 24V case WILL NOT work, I believe the hole for the VP is a different size than the p7100. The KDP problem might not be a problem, depends if you buy a used 12V case or not. The new 12V cases from Cummins have a blind hole now that remedies the tab issue. That being said, 10 minutes with a grinder and a pair of visegrips can make you a tab for free.