I dont think you will have any issues with a high volume pump but before buying something like that ask yourself why you need it. How will a high volume pump benefit your current engine set up? Why not high pressure as apposed to high volume? You dont need to answer that......just saying talk to some engine builders and get educated.
An oil cooler set up can be done any time. If all your doing is autocross you may not need it. You'll know after installing an oil temp gauge.
It's easy to spend in this hobby and if you are on a budget you'll want to spend smart. Keep us posted