I am considering getting my first laser cutter, but I have no idea what to choose.  It will be for thin wood used in both model rail and Rc Aero models.

Can someone please suggest one?

There are numerous threads on RMWeb about laser cutting - including a lengthy one on the popular Emblaser cutter.

https://www.rmweb.co.uk/community/index.php?/forum/180-3d-printing-laser-cutting-cad-cnc/

If I might offer some advice, first consider whether your modelling needs might be better served by a cheaper desktop cutter (eg Silhouette Cameo) or 3D printer (eg Anycubic Photon).