Hello and welcome!
I started with pretty much no knowledge of the sky, and I got myself a 10" Dob. I guess I'm more into planetary stuff that DSOs though so it doesn't really matter too much
I don't know anything about the LX90's, so I can't help you with that.
I'm fairly sure that to transport a 16"er around, you'd need a lot of room in your car. I can only just fit my 10"er in the back of our car.
Once again, welcome
