If you went that Pimp My Rice route, I can save you the money....
$10 for 5 gallons of fuel
$.75 for a lighter
$1 for a local paper
Get where this is going yet?
I have done custom rooftops, targas, and ttops back in the day and NO top has ever exceeded $8k, that I can recall. Of course, back then you were covering our $90hr labor, not that LA Thug Shop ("what is ASE?") $600hr labor. I am sure that the planning, design, and modification work will take a hell of a lot longer than anything I ever worked with, but $100k sounds outrageous. Now let's say you decided to go for it anyways.... think reputable. Look at shop credentials. Some of the shops you see on tv are circus shows. I guarantee 10% of the employees are actually trained and certified. Sometimes, those OJT guys may be good, but I need guarantee behind that work. You spend that money, you need to aim higher at someone like Foose. If a shop has too many shiny things in the windows and 20 lowriding, multicolored MODERN cars in the lot, run for your life. :P
Beinga hip hop guy like you say you are though, and if it's just that rep you are trying to uphold, its your call. I would take reputation of a shop over "but these guys do all the rappers cars!" any day.