freestyle unicycle

my old unicycle broke so i need a new one

i am 5 feet tall so do i need a shorter unicycle? wat should b the wheel size ?
i weigh 90 pounds and im 13 so do i need a lightweight uni or wat?
im willing to spend 150 dollars
thx

Torker LX with a cut down seat post, very easy to do with a pipe cutter or a hacksaw.

http://www.unicycle.com/shopping/shopexd.asp?id=634

Chase