first of all the reason the rims you chose are only 500yen is because they are sized WAY small. I feel you would probably be dissapointed with the wheels when they arrive (I know I was) My suggestion to you would be to look for larger size wheels (they should say 18in.) so they look right. the price difference shouldn't be enough to make you unable to purchase, I think it's only like $1 more.
suggestions... for the S13 I would think these look good...
http://www.hlj.com/cgi-perl/hljpage.cgi?AOS31131
http://www.hlj.com/cgi-perl/hljpage.cgi?FUJ19211
I LOVE these (who doesn't) (they are the one's on my S15, but I gold plated them with yellow acrylic)
http://www.hlj.com/cgi-perl/hljpage.cgi?FUJ19194