My suggestion is just compare the petrol & CNG consumption in both JDM & PDM Alto, you will never think to buy one,
PDM Alto is old carb. technology, can just go to 10km/ltr on petrol, better average on CNG, even charade & swift are better than this.
JDM alto has a number of options in its class but petrol & CNG consumption is very high,i.e.; 200rs CNG for 40km
no doubt it is comfortable, but both type of Alto's will kill your back in long routes...
prices of both cars are high as compared to its class/category/comfort