There was never an official study guide or practice exam for the CCSPA that I can recall.
The CCSPA is very "CISSP-like" in that it covers high-level, vendor-neutral security concepts as opposed to CCSA/CCSE/CCSM which covers the specific details of designing and implementing Check Point solutions. So CCSA/CCSE-based knowledge will only indirectly help on the CCSPA exam at the conceptual level.
Your best bet is to directly buy the CCSPA electronic coursebook for $200 USD at pricelist.checkpoint.com under the "Training" tab where you can order electronic "Courseware Kits". Looks like you can select and add the CCSPA courseware to a cart, then request a quote (but not actually pay online though) so I assume a reseller or Check Point themselves would collect payment at that stage and complete the order fulfillment.
Gateway Performance Optimization R81.20 Course
now available at maxpowerfirewalls.com