Soon 16, which 125cc? Yamaha YZF R – 125 or Vll. Aprilia RS 125?

Hey guys, I’m going to do my A1 and I’m 16 xD in 6 moats. But I’m one of those who have decided for some time, and then, when it’s time, I know what they want. So, I saw the Yamaha YZF R – 125 the other day, and I was totally overwhelmed. Today I was at the Yamaha store and sat on it, feeling really comfortable =). But do you get a crooked back or back pain after a time? Above all, I’m 189 – 192 cm tall and weigh 135 kg. But now some thought that I should buy the Aprilia RS 125, because it has 34 hp and 160 – 180 km/h. These are already good arguments, because the Yamaha has only 15 hp and drives unrestricted “only” 120 kmh. But the Yamaha needs less gasoline again, even if it is not the world, that is racing after a time. But what is also right for the Yamaha, the price. Because the Yamaha costs new 3899 €, ars** expensive. But the Aprilia RS 125 2006 costs new I gl aub 4800 €? Haven’t really seen each other in the price range yet. But which one can you recommend to me? One of the two or another?? Hope for answers =) Best regards curtisSs