that said, consider putting a bose 901 driver load in a more conventional "box" that meets your dimension requirements.
I want bass and mediocre or average/decent not spectacular treble so I would say the first.
If you want really LOUD (rock concert-levels) sound with good bass extension then you want high efficiency and high power handling, and i'm afraid this is not possible with small boxes. What you want is disco-club-sized PA speakers like the ones made by JBL.
But your ears will be gone in no time.
so, it sound like you want sheer volume. If that the case don't get overly focused on interpreting wattage as volume. Efficiency is probably more important that wattage specs, as a 91db sensitivity speaker will be be approximately twice as loud an a speaker with an 88db sensitivity rating. and a 94db speaker will be twice the percieved volume as the 91db speaker in the same envirinement. So, an 88db sensitivity rated speaker that is capable of 100 watts RMS wont be able to keep up with a 94db speaker rated at 50 watts. You have to look at the big picture.
Ever heard of Legend, Hot Spot, or Bullfrog monitors?lol!! :d