the brakes will work, but it's best to grab the control arms, too, or at least the upper, and spindle, of course. If you use the later lower, the sway bar bracket is reversed from earlier style. you can use the earlier sway bar, or maybe if you cut a hole in the cross member, you can use the later (bigger dia)sway bar. I don't know why somebody would say you have to mod the firewall, unless they are just talking about the pinch weld. Of course the tunnel is a different matter. There's no denying the trans body/tail is longer to accommodate the OD, that's going to require some extra fabbing.
As far as the color goes, it's your car, paint it any color you like. Just consider what looks good on a Viper, may not look as good on your car.
