Buying a good conditioned (second hand) Honda or CHonda 125, adding disc brake at front, experiments with rear shocks, the overall cost reaches at a level where you would need to add few more bucks and you are good to purchase a very neat condition YBR (as its resale is not that good at the moment). With YBR you will have peace of mind, comfort.
The other way, adding a disc brake at front on CG can be done in two ways. Either you install disc brake on the stock jump bottles by using custom made steel rod to hold the caliper. All you need to buy, the disc brake setup, hub, speedometer machine. Made in China complete setup will cost you not more than Rs.4000 (that steel rod thing is not included).
Or you need to do little research and hunt for the bottles. Find bottles having bolt fittings to hold the calliper, matches the rod dia and the overall fitting.
I am really not sure about the fitting of Dlx setup, you might need to research on the length of jump and overall fitting like the T fitting. It will cost you much more.