Need to check security and server capability of incoming project.
Need DDoS attack, at precise date & hour.
Open to your offers.
If you need to check security and stability, why do you need an actual attack performed?
You'd be better off working with a consultant if this is legit, and there are ways to loadtest your system without using questionable means such as DDoS attacks (which could very well involve botnets and thus be illegal).
Having said that, i'd happily give you a security audit and assessment for about 10BTC including full recommendations on how to keep your site operational. Please PM me with the URL and proof of ownership and we can discuss.