The first thing i would suggest tryin is to get some sound dampining mat. you can get it at some computer stores(compusa has it) and alot of auto stores. It comes in sheets adhesive sheets that you just put on the inside of your case. This way you may be able to leave your system as you have it and kill some noise. But you will still hear most of the fan noise as you cant really cover those up.
Second id look into fan throttling software or hard ware. If you have the space get a fanbus. Then you can still have all the power but you will only use it when needed.
Thirdly and my personal fav fancy and nee Innovatek water cooling