1. Jango Fett is a better assasin because thats preety much in his job description.
2. Darth Maul would win in a head to head battle.
3. Darth Maul would be able to track down Jango. And kill him.
Nute Gunray:" My Lord, it's impossible to locate the ship. It's out of our range."
Darth Sidious:"...not for a Sith..."
A second SITH LORD appears behind DARTH SIDIOUS.
Darth Sidious : "This is my apprentice. Darth Maul. He
will find your lost ship."
4.Jango would be able to track Darth Maul down but not kill him.
At last we will reveal ourselves to the Jedi. At last we will have revenge.