Modifying out a 2003 Starcraft BUS .... HELP!

[BulldogPI]

So I am a new member of the #Buslife movement, although I don't intend to live in the thing fulltime. I have a Standard Starcraft 2003. It has a 6.8L Gasoline engine (v10). I want to modify? replace? the current ceiling, and can provide images of it but I think it's just a standard stock, fabric type of ceiling. What I want to do is install more/better interior lights on a separate switch. I got some very nice ones off Amazon, 12Volt 3 watt. They should do the job nicely... but what will I get into if I start to remove the fabric ceiling? Is there currently a wiring space between the fabric and the fiberglass above? I also don't know what to do with the old A/C unit towards the back or if it's salvageable. I could use some help here.

Maybe I posted this in the wrong place? It's currently a Shuttle Bus, not an RV... I want to make it an RV of sorts.