I dont know about sourcing, but i thought i can help you advising that 255 = 255mm and hence 10mm difference = 1 cm difference in tire width. If you like you can change to that size as its perfectly normal and acceptable to change tires with little size difference.
My advise is 2009, not only for stainless steel exhaust but for the sake of getting 3 years more life. No offence to Aveo or your choice, but economy cars like have best life in first 5 years and after that lot of maintenence comes from repair, replace and breaking parts.