CRF150R vs. CRF250R

I'm obviously new to this forum, but I needed advice on a certain situation that is developing amongst my family. Currently, my family owns three different bikes. We have a Honda CRF230F, a Honda CRF70F, and a Kawasaki KX65. Normally I ride the CRF230F around my house (we have 4 acres of land), however, lately my brother, my father, and I have been venturing to the local MX track close to my house. The CRF230F is simply too heavy to handle the technical aspects of a motocross track. I have also gotten bored with the power delivery, it's just too pedestrian. There's no pep, not enough tourque. I guess I'm ready for something more. My question is this: would the CRF150R or the CRF250R be the better bike for me? I am short (5'6'') but I wrestle and if I can throw around the 230, I am sure I can handle the 150 quite easily. But would the 250 be too much bike for me? Could I lower the suspension a little or adjust the sag so it's a little more rideable? I weigh about 135lbs. Thanks for any and all replies. I really appreciate it.
1) your physical size (both height and weight are important) - 5'6" tall. 135 lbs. Wrestling build.
2) How physical / aggressive are you ? - about as aggressive as I can get with the CRF230F
3) what do you plan to ride- MX/SX tracks, woods, fields with friends or ???? - local MX track. 230 is for the woods.
4) Do you have any riding experience? - yes. a couple years.
5) Do you think you will race ? - probably not but who knows.
6) Are you mechanically inclined and will you be doing your own bike work? - yes. my dad knows a ton about 2 and 4 stroke motors.
7) Do YOU have a preferance to a brand/ motor choice (2 or 4 stroke)? - Honda. maybe KTM? probably 4 stroke from what I here. anyone think differently? maybe a CR125?
8) Do you have a dealer close by your home that you might use and what brand(s) does he carry? - yes. all brands.
9) How much ($) do you plan to spend on a bike? - depends on which bike I get.
10) Do you live in California? - PA
11) Your age? - 17
12) anything else that you think would help form an opinion - see above.

THANKS AGAIN!!
Jon H.

Thanks so much for all of the replies. Everything that you guys had to say really makes sense. I think we're going to try to go with the 250R even though the mark up on it is quite a bit more. I think I'd get too bored with the 150R. Does anybody know what specific parts or procedures could be done/bought in order to lower the bike a bit to make it more rideable? specific brands and part names would be greatly appreciated! thanks again for all replies. flyingfuzzball, i wrestle for a small catholic school in Delaware called Archmere Academy. we arent very good as a team but every team has to start somewhere. we compete with schools including St. Marks, Caravel Academy, and Salasianum within our conference.

DougRoost, i like your idea(s) about a 125, used or new. either way, they are significantly less expensive than 250 4 strokes and since i probably wont be racing, the performance that a 125/144/165 2 stroke can offer would probably be more than enough for me to gain more experience on. i also agree with your points about having to utilize more skill to shift/clutch to keep the the bike's rpms high through technical corners/jumps. where would you look to try to find a good quality used 2 (or 4) stroke bike? im looking for something that is between a 2005 model year and a 2007. ****? the daily paper? thanks for any response.

Jon H.