N Gauge Mk1 Coaches

[airfix27ra]

I wish to make up a set of Network Rail inspection coaches.
I need 3 coaches all the same length. Now I am not sure
how many different length of coaches there are, I have both 119mm & 130mm ones.
Probably the shorter ones will be better, as it then keeps the overall train length down.
Where I am buying the stickers from will print them off to the length of coaches I have.
The colour is also not important as they will be covered with stickers. The age is also not
important, as long as they run smooth.
Keeping fingers crossed.