I am considering purchasing a 2004 Specialized Hardrock SS BRAND NEW with disc brakes, Marzocchi fork etc for $350. Is this a good price for this bike? Also, it is only available in 17" and 15". I am almost 5'8" and a girl. I know I should be properly fitted, but this is from out of town and I won't be able to. Just knowing that I am a girl and about 5'7 1/2" tall which one would you get?