The three sites listed above are the best options. You may also find others you like here: https://kycnot.me/

Speaking more generally, you will struggle to make a single trade for $10k worth if you are brand new to these platforms. Established traders will be understandably hesitant to trade large volumes with a brand new user with no trading history. The best option is to use these platforms long term to build up age and reputation on your account, although I appreciate that doesn't help you in the short term.

Trading options can also be limited depending on your geographical location. Try broadening your search. If you don't find any offers you like, then consider posting your own and waiting for someone to accept it.

You could also try the Currency Exchange board on this forum (https://bitcointalk.org/index.php?board=53.0), but again, as a brand new account with no reputation you will almost certainly need to use an escrow for your trades.