Your set is good. When you have more consistency in your swing, then you can consider getting clubs that can be customized for you. Work on your fundamentals and try to break 100 with that set.
The most important thing for a beginner regarding clubs is that the shaft is not too stiff for you and that the driver loft isn't sub 10 degrees. If there is anything to change, I would start with the putter - if it doesn't feel right, you will have issues (you will use it at least 36 times a round, and more if you don't putt well).
Lastly, I have achieved better consistency in a shorter period of time using the 3W or 5W from the teebox than the driver. The driver is a good tool for finding the worst parts of the course (woods, pine needles, water, sand, deep rough, other fairways).
You don't need the Mizuno MP-900 or Callaway Fusions to play any better.
Nicklaus EZ-UP Irons Irons - Golf Clubs & Golf Equipment Reviews 2005-09-29 Nicklaus Air Max 460 DPT Drivers - Golf Clubs & Golf Equipment Reviews 2006-06-07