Oops, forgot the 255/50/17 was 27" tall, you wanted 28.

there's a 275/50/17 that's a shade under 28" made by Falken, it's not too expensive.

http://www.rims4less.com/proddetail.php?...3807129717c171d


There's some 255/55/17 tires from brands like Pirelli but you'll pay about twice as much to get that "exactly 28-inch tall tire"