Its getting damn hard to find any tire for skinny wheels for a 15" wheel. I know it sucks. They still make 165's and 155's because of old VW beetles running around but most of them have upgraded. You pretty much need to buy "vintage" car tires. I can't seem to find anything in a 15" rim that is thinner than a 185/65R15 and that is still too wide on a 4" wide wheel. You don't want to put too much tire on a wheel, it defeats the purpose.
You can look up Mickey Thompson's Sportsman series, but those are expensive. So are the Moroso's and such but these skinnies need some traction.
I would see about getting a wider wheel up front, like at least a 15x5", that would give you alot more options.