As far as you display the numbers under a SSL connection, there is no problem.
A secure connection is established between your client computer and your webserver.
1. Clients fill data and submits over secure SSL connection
2. Your confirmation script collects the data and stores in hidden fields and display text for conformation.
3. Clients confirm the data and submit
4. Your processing script enters order details into database and calls paypal pro functions.
As long as the above are done on a secure ssl connection, there is no problem.