Single rotor (2 blade) helicopters?

I had the 72 and 48 scale uh-1n.  the kit is ok, if you don't mind making the few parts that don't usually come with the kits.  i also worked on the uh-1n for air rescue, so i know about the extras that were needed

1/48 Bell 222/Air Wolf

Although significantly narrower than your Hueys, the 1/48 AH-1G (Lindberg and Aurora), AH-1J (Fujimi), AH-1S (Monogram), AH-1T (Italeri), AH-1W (Italeri) are similar in height and length.

Ooh yes an AH-1 would be good.  The width is important though, as are all the dimensions really, anything smaller in width/height than a 1/48 Huey would be too small and a tail boom longer than the Huey isn't ideal either, although usable.  A 1/48 Bell 222 isn't quite wide enough at the top, nor is an AH-1 in 1/48.

1/35 scale probably would be though but I don't want to go too large, and I fear the 1/35 scale AH-1 and Bell 222 would be larger than I want.

I'd forgotten about those two to be honest though - should have mentioned them...

Struggling to think of any others though.