Those are obviously Japanese builds. Low riders seem very popular in that part of the world. You'll have to piece things together...as the builders of those heavily-customized bike did. If you know what to look for, some parts can be found on ebay. The bulk of the ST70 Dax & CF70 Chaly stuff is available from sources like Web!ke.
Dropping the ride height is easy enough...stock CT70 shocks are 330mm, just look for shorter shocks; dropping down to 280mm will knock ~2" off the rear end ride height. Z50 lower/inner fork legs can be adapted to fit CT70 K0 upper/outer fork units. That's the easy part. The difficult part is making everything work. First off, you must maintain tire-to-frame/fork clearance when the suspension bottoms out...or you'll pay dearly for the oversight. Then there's real world viability. Lowering the ride height reduces the functional capacity of the suspension. At best, the ride will be far stiffer/less compliant, more jarring and the bike will be more easily susceptible to road damage. Then, of course, there's clearance to consider...not much fun when an $800 titanium exhaust pipe sustains road rash. I may be wrong but, I cannot imagine a country like Japan allowing their roads to deteriorate to the point that I see all over the US of A, including where I live. What I'm saying is, carefully consider how you want to use the bike, once it's built. If you have smooth, well-maintained roads or/and primarily want to show the bike, then going true "lowrider" style makes more sense than if your goal is serious riding. Not everyone wants the same kind of machine.
