Anyone who guarantees that is selling you snake oil. NO ONE can guarantee placement on Google. There are techniques that can improve your chances, but it is impossible to give a guarantee. There are so many factors contributing to ranking that it takes a very good plan to accomplish number 1 placement. You have to look at what the competition is doing and then build a strategy around Link Building, Content Creation, and Solid Activity to influence Google. Every site is different so think first about who is the best target market for you and build your strategy for that one person