If you are a do-it-yourself type, a teardrop is a pretty easy thing to build. Any it's not particularly hard to keep the weight down. 300 Lb would be enough for a over-nighter, and 500 pounds if you don't need everything including the kitchen sink. There are plenty of light-weight builds that are holding up just fine over on the teardrop forum. The nice thing about a teardrop in particular, is that the shape adds to the stiffness and strength. Curved panels are much stiffer than flat ones. Many of the vintage trailers only used 1/8 skins under the thin sheet metal and they are still going after 50+ years. The aerodynamic loads are relatively low and, if kept light, the dynamic loads from the road are also low.
If I were doing a trailer for the Chevy truck I'd do a TTT (with Al skins -- they look so good), otherwise a small tear for the smart seems like it would be a good match (looks and functionally).