I have started planning a couple of 1:144 projects- a Boeing 307 and a Republic XR-12. I bought a sale priced B-17 to use parts for the 307, but boy, I sure can't find much usable out there for the XR-12. There is a ton of aftermarket stuff out there for 1:72, 1:48, and 1:32. Not much for 1:144 though. Hopefully as more kits are available for the scale, more of the aftermarket stuff will follow. We need engines, wheels and landing gear, and props.
I am doing all commercial stuff smaller than DC-3 in 1:72, but everything DC-3 and larger in 1:144 scale now. Otherwise the collection of built stuff- already large- would take over my house!