Cotterless cranks should all be the same size and interchangeable. So yes, you should just be able to buy an off the shelf set. You will need to get an appropriate crank puller or take the uni to a bike shop and have them remove the cranks; which might be cheaper if you don’t plan on changing the cranks out again. There is a cool set of 125/150mm two hole cotterless cranks by Standard High Wheel that might interest you. They are discussed in this topic: Dual hole 125/150 square taper (cotterless) cranks