A 4WD variant consumes more fuel than a 2WD, and drive feels more "heavy". These variants are cheaper in price than 2WD.
Regarding 997 vs 1300, If both are 2WD, I would strongly recommend the 1.3L variant. With heavy body, a 1000CC engine always runs at higher RPMs, consuming more fuel and lacking power.
P.S: Expecting 18kpl in city drive from a non-hybrid car is too optimistic