Another site with FREE ones to use.
Most of these are Royalty free so you can use in Payware too.
You might want to manually edit the triangles and add some LODs tho. Textures might need to be changed from Opaque to Blend using MSFS Standard if you use Blender.
LODs need to be created manually in Blender or whatever you use!
To manually adjust the LOD’s you use the .XML file
Example:
<LODS>
<LOD ModelFile="yourmodel_LOD00.gltf" minSize="8"/>
<LOD ModelFile="yourmodel_LOD01.gltf" minSize="4"/>
<LOD ModelFile="yourmodel_LOD02.gltf" minSize="0"/>
</LODS>
With the minSize corresponding to the screen size when it switches so at 8% screen size this will go to the next LOD. Then 4% then the last one forever!