I speak only from personal experience, albeit bringing a dog (not pup) from west to east (WYO -UK).
I spent many hours researching the how to do for accompanying a dog on the same flight. The whole rigmarole made it virtually impossible - remember the rules are to a large part designed by animal shipping agencies. Was I glad that I opted to use shippers - definite Yes --- although it would have been a substantial money saver to fly out and accompany dog on same flight.(Much easier from East coast airports to main EU airports such as Schippol, Holland on DIRECT flight.)
Although you might book this arrangement - it may not happen that way !... eg you book your ticket with Airline A but they share some flights on that route with Airline B and you may end up on different flight to your cargo/dog. Double check to exclude that possibility might arise.
The primary obstacles to me were the import rules post Brexit. Would have been far simpler for a USA to EU shipping. From memory I think that American Airlines had the more straightforward procedures and access to information for private individual shipping requests.
I have flown long haul (UK - AUS) as handler in attendance with dogs as cargo and the flight itself is not an issue for the dog. I would not anticipate problems of stress on pup for your relatively short haul trip - assuming no unexpected/undue delays. You have to RELY (?) on baggage handlers to be sympathetic and professional in the load and unload procedures and to ensure a speedy process.
My 2c ?
1.The older the pup the better for travelling.
2.I would be apprehensive of long distance shipping for a nervous type of pup.
3. Arrange travel outwith the season of high ambient temperatures in case dog has to spend a length of time on the tarmac during loading. This is important.
4. O-W-D makes the very pertinent point about buying "blind" - may work out well for you but it might also turn out as "pig-in-a-poke". In the latter case - just think of the next 12 years.!!
Good Luck.
