another 1st bike thing help is appreciated

1) your physical size (both height and weight are important)
5' 6'' 115 to 120 lbs.
2) How physical / aggressive are you ?
very most of the time especially with vehicles
3) what do you plan to ride- MX/SX tracks, woods, fields with friends or ?????
mx/sx and messin around in trails
4) Do you have any riding experience?
just a little messin around with 80's and 70's but have been on 2 wheels all my life with bmx bikes
5) Do you think you will race ?
yes at a local track every sunday
6) Are you mechanically inclined and will you be doing your own bike work?
i will be learning from db friends and learn any other way i can so yes
7) Do YOU have a preferance to a brand/ motor choice (2 or 4 stroke)?
i was lookin at a crf150r or kx100 i would prefer a 2 stroke but it depends on if 2 strokes will be illegal soon
8) Do you have a dealer close by your home that you might use and what brand(s) does he carry?
yes all
9) How much do you plan to spend on a bike?
no price limit
10) anything else that you think would help form an opinion
only that i want a bike that i can fit now but also when i grow 3 or 6 inches

ok that helps a lot and the only thing im afraid of is when i first get it im gettin 1 for sure the beginning of spring i will then practice and race at a local track this summer and im afraid it will be too big and i will have 2 tip the bike completely sidways just 2 touch the ground also wat about a kx 100?

now back 2 the 2 or 4 stroke ? all my friends around here say 4 strokes are "in" and better but personally i would prefer a 2 stroke y do they think 4 strokes r better