On any significant trip like that you need to check out
avgas
landing ppr
customs ppr
for each proposed airport.
To find out the info, you can use various methods:
- national AIPs (hard work and often inaccurate)
- Navbox has airport contact details and indicates the PPR requirements (mostly accurate)
- the ACUKWIK airport directory (mostly accurate on the contact numbers especially re handling agents)
- Jeppview Text Pages (often out of date)
- phone/fax/email/AFTN the airport itself (the best way by far, but getting through can take time, and many never respond)
If you can speak the national language, phoning each airport is the best way.