1. Sequential turbos are mostly used on bigger motors (think 2jz) or diesel guys use them too with their bat shit crazy stuff http://www.dragzine.com/news/wild-9-second-triple-turbo-duramax-diesel-powered-chevy-nova/
2. Single turbo with nitrous is usually something you see with the above because they need to "light" the turbo, or with diesel guys its because of the giant turbo and engine combo. You don't want a turbo that is to big for the small motor with something that will see street duty, you will hate it.
3. Go to work on Monday and punch that coworker in the throat so he can't say stupid things anymore.
I'm not going to be critical of your build, its your money, at least you doing car things with it.
If your heart is set on a SRT Neon, keep it simple, a good single turbo, with good engine parts and have fun.
Never dump cubic dollars into a pie in the sky dream nobody else has done, your project never gets done or never meets your goals unless you have the money.