personally, I don't like it because it's a 15''
to me it looks like a wheel coming from some cheap truck/van/SUV

no offense, I am not a fan of 15'' rims, even 16'' are not too nice to my eye. and understand my point of view, wife's car uses 15'' alloys and mine uses 16'' alloys
I bought some cheap (~$70ish each) 205/65/R15 tires for my wife's 15'' rims (OEM alloys) from
www.tirerack.com
they were Dunlop SP Sport Signature 94V 460 AA A. Not a beautiful tire either, but at least it's cheap and have good traction/wear/speed rating parameters.
I wouldn't spend too much on 15'' tires, check ratings and user reviews on tirerack.com and then try tracking them down in your area.
225/60/15 sounds interesting though, especially on your wider rim, it could be looking interesting

however I think 225/55/15 might look better if it fits?