Trying to keep my china girl running has been a chore. Still, I enjoy tinkering and this kit has allowed me to (constantly) do that. If you end up buying a Chinese frame-mount kit, be sure to immediately replace the drive chain, spark plug, and acorn nuts. The stock chains are very low-grade metal. The stock plugs, though functional, are of the lowest quality I've ever seen. The acorn nuts don't allow you to fully tighten your head to spec, not to mention the fact that they strip out with the smallest amount of force. I also recommend replacing the motor mount studs and nuts, as these are prone to bending and stripping. The stock mufflers have VERY bad welds. After the guts fell out of my muffler, I repaired the muffler internals, only to have the ENTIRE MUFFLER break off only a few days later! The stock CDI is prone to frying, so don't hook ANYTHING to the white wire. You may want to keep a spare CDI (about $10) on hand with your riding tools. Yes, you MUST have "riding tools". (A small ratchet with a 10mm socket, a pair of pliers, a multi-bit screw driver, and an adjustable wrench are the least you will need to bring) Always check and tighten all bolts before each and every ride. I think I've covered most of the basics of keeping a Chinese kit going. I haven't mentioned oil/fuel mixture, or air/fuel mixture, both of which will need to be just right.
An easier and somewhat more reliable option is that of the friction drive kit. My first FD build cost me no more than $30 excluding fuel/oil. I bought a used Schwinn for $20, and somebody gave me an old Ryobi weed-eater for free! The other $10 was for mounting materials. I used wood for my mounting medium, and it worked great, except for some eventual cracking (after several hundred miles of riding).
I started with a friction drive I built from a Ryobi 30cc 2 stroke weed-whacker engine. That motor ran great for about 600-700 miles worth of riding, then I broke the crank shaft due to the fact that I had a flat spot on my rim. (If you bend your driven rim on an FD bike, always repair/replace it immediately.) Until that point, the only trouble I ever had with it was a bad carb diaphragm. I've since converted three other leaf blower/weed eater motors to friction drive systems, and once again, the only troubles I've had are carb related. Carb problems are a pretty easy fix. (An entire carb rebuild kit which fits most 2-stroke carbs only costs $9.99 at Home Depot.)
I got into motorized bicycles because I needed cheap transportation. I started last spring, and I'm still riding them to this day. I must warn you, I've had grease on my hands just about every day since then.
I wish you luck on your first build, and on your potential new job.