215/45 is not much of a stretch at all.. but it also depends on the brand/model of the tires as different tires stretch differently. Since you're going with springs.. just go with 225/40 to give it more of a straight tire/rim look. If I were you.. I would save up for some coilovers. Some could be had for about 600. There's the new Megan EZ Streets for $650. Give those a look.