I got mehran VX in december 2011 WITHOUT CNG, because of following reasons:
1- 40 Kg Cylinder
2- 61K extra just for CNG
I got CNG fitted from Pakistan CNG here in islamabad for 35000, Landi Renzo Italy KIT and EKC cylinder 50 Kg, and the fitting was no way less then the factory one... On cng my ride gives me 210 km in one cylinder in Islamabad/Rawalpindi, last weekend coming back from karkhano... i got my ride fueled from hayatabad and and travelled back to islamabad in just one cylinder (245kms).....
Bro i am completely satisfied from CNG from market. Rest is ur priority