Confused Turtle

So to start off I wasn't quite sure which category this post would fall under so I apologize if I started in the wrong forum area.

After tearing apart the bottom end of my car, I've discovered my 99 Boxster needs to get rebuilt. So I am currently looking for any advice on parts to modify or add specifically to add to the cooling and added durability of the engine in a lower moderate budget. My aim is to modify it for SPB and also for Champ Car. I realize I will be starting with negative laps this way but I am willing to start with that. Here is where I am starting at with parts.

IMS upgrade kit
3rd radiator
connecting rod and crankshaft bearings.
Replacing ALL of the gaskets.
Deep oil sump
Boxster s oil cooler
Valve lifters (not aftermarket, just new)
(debating on accusump oil accumulator)
is there an upgraded pump or do i have to stick with stock?

Any advice on brands or changing out different parts for newer ones would be appreciated. I am a new 986 owner and still learning the nuances of the car.

Thanks in advance!