lol, but Sansar is not too much like SL right? At least not anytime soon, or maybe ever, it wont have but a tiny fraction of the abilities and features, SL is mature, and will more likely benefit from back-porting some of the Sansar development than be replaced by it.
To the OP, I would recommend the Zimberlab kits too, makes mesh mostly an in-world paradigm, and its all full perms. I have most of them but actually prefer using blender for constructing builds myself, I will mix in some zimberlab stuff here and there tho, love their doors, stairs, and the convenience of the wall kits for making interior floorplans and such. I built a bunch of different things with it before deciding to go 99% blender. Blenders toolset is awesome, you can squeeze out prim usage and have amazing control over details, baking normals for added detail, creating your custom LOD, and so much more. Good luck on your blender studies!