I wouldn't get a gas shock. There is more pressure with those and the mountings for shocks on an Airstream isn't exactly heavy duty.
I took my old shocks to NAPA and they matched it for dimensions to sell me replacement shocks. I don't have that daat as it was a long time ago.
1966 Mercury Park Lane 4 DR Breezeway 410 4V, C-6, 2.80 - Streamless.
1966 Lincoln 4 door Convertible 462 4V 1971 Ford LTD Convertible 429 4V Phoenix ~ Yeah it's hot however it's a dry heat!