Items ranging to New Supplier

Dear Support Team,

We are on RMS 12.0.10 and would like to know the possibilities on below scenarios

1. 20,000 items has been ranged to X supplier, Now we would like range the same items for Y supplier.

2. After ranging the items to new supplier, Create a New PO for 20 K items to WH. Is it possible to create PO for 20k items in RMS?(Is it possible with Item List, All items having different quantity)

Please let us know What is the recommended way to achieve above steps and  Kindly provide us the steps to perform the same.

Regards,

Sravan