SX4 with Fiat Multi-jet engine (Well okk.. Suzuki DDi or whatever its called) would have been the perfect choice - considering your 1000 km per month running on city / highway / rough roads. Also, remember that SX4 was a joint development by Fiat and Suzuki . But only problem is Maruti cant make enough of SX4 petrol itself to meet the current demand, forget about Diesel !! So you can opt for SX4 petrol, but u may end up waiting for delivery as well!!
About the ride quality, I have driven my cousin's SX4 with 18inch alloys
(http://www.team-bhp.com/forum/modifications-accessories/24291-my-sx4-18-inch-rims.html) (MY SX4 with 18 inch rims)
After that, I really don't know where is this talk about hard ride quality is coming from!!