97 civic EX Sub Install Questions?

Ok now that I have everything ready I need to ask one question.  I beleive that I want to install my 10 L7 in a false floor box in my car.  i have all the room in the world in the trunk but because the spare tire well goes the entire length of the trunk and i build a small or big box there.  The thing that I need to know is wether to build the box completely out of mdf or do a combination of fiberglass and MDF.  My goal is to have a usable trunk when finished.  here is all the equipment that will be put in there.....presumably under the false floor

• 10" Kicker L7
• Rockford 500bd
• Rockford 750X or 550X (havent decided yet)
• Homebrew computer for MP3 (doesnt take up a whole lot of space)
• 1 Rockford 1 Farad Cap with digtial Readout

would it be better to build most of the box out of fiberglass and use the MDF as the false floor.  or should i just build the whole thing out of mdf?

Thanks in advance

~Q