Tires for 15x3.5" wheels

this may be a stupid question,but what difference does tire height in the front matter,other than looks?

A taller tire will have a bigger sidewall. This will ride slightly better due to being able to absorb and cusion more and at the same time handle slightly worse due to being a little more mushy.

Go with the 165R15 or 165/80R-15 (same size tires). There are a lot of different manufactures. eBay can get you a pair delivered in the U.S. starting at $120.00 and go up to about $180.00 for the more expensive ones.