Bubba has it about right, on average, provided the have the money for the paint work, it can usually be done in about 3 months. I will, however, warn you, if you don’t have experience working on or building bikes, I would learn first before attempting a project like this. I have had to take apart and completely rebuild entire bikes because auto and aviation techs usually have the mindframe they think bikes are simple…compared to most of today’s cars, they are, BUT….if you don’t know how to properly align a drivetrain (eng-to-frame, trans-to-frame, eng-to-trans, axle-to-frame), align a primary drive, front-to-rear sprocket alignment, caliper-to-rotor aligment, set steeering neck tension, check wheel bearing endplay, proper wiring & soldering techniques, wire routing, etc……the project can be a nightmare, normally the bike needs to be fully and properly assembled to make sure everything fits the way it should and in alignment ( this is called a mock-up build), then completely disassembled, sent out for paint, and then put back together. On top of that, most of the kits on the market are on the chep side, meaning they don’t cost much up front because they use alot of “taiwan-ese” parts. Also, when you do a build like this, there is not much of a warranty, if any, so if something goes wrong, you are pretty much screwed. Another thing to take into consideration is titleing and insuring the bike, in some states, this can be an absolute nightmare.
I am not trying to scare you off the project, but I see this alot, and from my experiences, the people would have been better off either having a reputable shop do the build, or just simply buy a bike.
Oh, if you guys do decide to take on the project, KEEP EVERY SINGLE PAPER THAT COMES WITH THE KIT…..if and when you need replacement parts, if you don’t have the paperwork with part numbers, you will have one hell of a time finding replacement parts.