I'd add that I'd ask to see the form the shop uses to perform a PPI. Does it include a leakdown test, compression test? Cam deviation test?
My PPI was a two page written sheet filled out and they spent about a half hour doing a walk through with me while the car was on a lift even considering it was my second Boxster. It set me up to know what I'd want done in the next year or so. $3k later I was all set for the next 5 years except for the periodic fluids.
a list of P-car shops is
https://www.pcarshops.com/search?q=birmingham%20al