Revell do an Airbus A320 Martlesham do them.
Martlesham Models Scale Model Kits and Accessories: Aircraft Civilian (1:144)
I'm not a great lover of Condor Airlines, a lot of those no frills types don't have the class of a "proper" stewardess like me

. Sorry better be careful I might go off on one again.
I'm not sure if Antics in Coventry sell them as the first and only time we went there they had only just opened and it was mainly full of Die-cast stuff. Flea-bay is a good place and look out for Plastic Pastimes (polarbears3kitscatcat). They do a few airliners at times, that's where my 747's originate from.
Good question about the Two-Six decals. To be honest I'm not sure, I have only used some spare codes and letters from the big 747 sheet to do the Pan-Am Concorde. The instructions don't say either. I think I will proof just to be on the safe side and maybe with another 727 I might try naked, there is a terrible thought

, oops didn't mean it that way, soz!
To be honest there is a slight bleed on the American flag, should be negligible, I have enough of those from a 747/747sp/DC10/L1011 Billboard sheet if I have a problem.
Those windows are to die for on those Two-Six sheets. I really can't wait to decal now, though it's going to be more like nextweekend the way they are going.