Jaime, yes it is BF Goodrich that makes the 245 and 265/50-14 tires. They are the only ones I have found making a street tire in a big enough size. I have already flared the fenders (with the always capable help of tensandtwenties) but the 200sx axle in the car already fills them up with the 195/60-14s. What I had planned to do is widen two of the wheels I have to the inside, basically make a 14x8 front wheel drive offset pair.
Of course, if we go with the more radical idea of using a Maxima transaxle and making the car mid engine, all bets are off as to wheels and tires.