I tend to be more pragmatic in my approach, thinking in terms of borderline hardcore mileage (at least for a bike this size

). But that is not to say that I cannot empathize with your point of view. That's probably why my purple Dax started out with a bare $10 ST70 frame, coming in second place only to the NOS ignition key for the cheapest part of the project. It's also why my first CT70, a low-mileage/one-owner K1 is getting the 100-point/concours resto treatment, instead of being customized into a usable road machine as originally planned. There's a certain satisfaction in resurrecting total basket cases, too. I have an ST70 general export model in the works that should have been scrapped, in spite of the fact that it has the rare crank-off front end. If it had been a CT70, I would have kept walking. I'm sure the finished result will inspire cheers from some and catcalls from others. You need to do your projects as YOU see fit. My point (if there was one

) was to consider this project from more than one perspective. Even complex projects seem to have a natural tendency to sort themselves out when considered from multiple angles and given adequate time. There's a freshly painted green HK0 discussed in another thread, with the decals clearcoated in the wrong locations. I'd bet the guy's perspective was very different as the clearcoat went over the decals, compared to the next day...or whenever the decision was made to list the project on ebay.
The impression you've given is that this custom bike will be your
magnum opus CT project. Customs are never really finished. And, trust me on this point, odds are good that you'll change your mind at various points along the way, possibly discarding work you've already done. Hence, in the spirit of camaraderie, I'm asking the tough questions, maybe to the point of playing devil's advocate, at the outset. The only correct answers are yours, of course. I didn't know that Lifan bikes were widely known in the US market. That's an important hurdle to clear early-on. It could give you the opportunity to build the most refined Lifan CT70 clone bike in North America. Probably wouldn't hurt the feelings of the PRC bike crowd, either.
As for tire fitment, 120/90 x 10 will fit. I'm undecided about the look, unless you also run a +2 swingarm and increase ride height enough for a decent amount of fork leg excursion. Those changes restore the visual balance, as well as some of the chain slack adjustment range you'll lose with a stock length swingarm. The taller sidewalls will plush-out the ride quality a little, plus they'll absorb more punishment without rim damage than shorter sidewalls. If you run close to the engine's power limit, you will have to gear differently than if 4.00-10 or 110/80 x 10 had been