Everything you said is correct. The engine will be in other 125I models. A CDI will do nothing however. They are not restricted, and the programing (ign curve) is set. You can contact HPI Ign. HPI | Horse Power Ignition
http://www.hpi.be/ and ask them what they have for a Kymco 125I. These guys are TOP in the world at what they do.
The down side of dealing w/ them is they are so close to Amsterdam that they take ALOT of extended "holidays".
It's a golden opportunity for your bike if you can get together w/ HPI.
Next step is determine exactly what rollers are in your bike, and if they suit your need. Lighter is more rpm, and heavier is less. You can take your rollers to the local post office if you have to, and ask them to weigh a couple to get the weight. They are used to me doing this here.
Dr. Pulley does exactly what you hear. All good. BUT go one gram LIGHTER when you order yours. They "act " heavier than rollers.
After the roller deal is set start off dead stop, and run to top speed. Pay CLOSE attention to the "shift" feel, and rpms. You don't want to feel anything, or hear the rpm change.
Post up what you feel, and hear. I will be happy to walk thu cvt tuning w/ you.