I'd follow what you currently have, use it as a guide.
Your chassis may have a lot to do with the front/rear
oil pan decision.
For manifold height, find what you currently have on the manufacturers web page then look for the indicated height. Check the Ford site and the supplied manifold, find that height. The difference is how much hood clearance change you should have. Or at least it will be close. Often an air cleaner change will help with hood clearance.
The new TKO-600 will handle more torque but how you drive will have a lot to do with what you need.
Jim