Top Actors For A Book?

[all da way]

I am writing a book as a school project. I was curious that if the book were a movie, which top actors could play the main roles. I have some ideas, but i thought that i could ask for some others opinions.

Here are the main characters. (I've put a brief description of how i picture the characters.)
Thanks

(Jason)
About 5 foot 6 inches. More or Less.
Blond
About 15 years old.
Skinny, attractive


(Allison)
Jason's Sister
A little shorter than Jason
Similar in appearance to Jason.
Pretty.
About 13 years old. (just has to look around 13 maybe 14)



(Bad Guy - Name still unknown)
About 6 foot tall.
In his mid 40's
Dark hair.


(Lawyer)
Young male.
Looks to be a good guy. Ends up being enemy.



(Jason's Girlfriend)
15 years old.
Short and skinny.
Light skin with dark hair.



(Brett) Jason's best friend.
15 years old.
Tall with blond hair.




Additional Info: None of the characters mentioned above are gay. Hope you have some suggestions of good actors that i might not have thought of.


Thanks