for a conversion you need;
a gear,
an ECU (car computer)
complete wiring
meter
brake pedals
the conversion cost will ideally depend upon gear, ecu and meter price. it may vary from 30k to 70k. will have to check from bilal gunj. no, the conversion will not give any problem while driving.
an ideal scenario will be to sell this one off and buy an automatic one.
a 2007 liana will cost anywhere between 6 and 8 lacs depending upon buyer need and seller coz liana is a very slow car to sell