One more thing, Is there any advantage ( not looks) if I fit the 15 inches instead of 13 inches? I mean any increase in acceleration(or loss), road grip? and what about the ground clearence?
Well standard over here they come as 15" with 195/55 And off set 35-45 ET, So this is a good guideline. But the lower profile you have will give you extra firmness because it gives you less flex in the sude walls as there smaller/stronger.
With 15" you will also get increased width when ever your wheel gets larger in Diameter so this is going to give you extra grip and stability. Should be fine with acceleration as they with 15" from Suzuki UK.
Personally id save up a little and go to your Motor/wheel shop and buy NEW once you tell them what car you have you can select from a load of wheels that are going to fit on no problems and can choose what tyres your want and ready to fit when they arrive. Mine cost me £400 with TOYO tyres.