What you think is irrelavent. 90% of SPL performance is in the enclosure.
Yes, the W7 is a good sub. However there are several problems with this guy getting one.
1) Price: There are several woofers out there that will give you the same level of performance for half the price or less. (TC3000, Fi Q, SI Mag, etc.)
2) It is harder to make a W7 sound good than it is for many other subs. You can get very nice output and quality with a W7, but (from what I've read) it requires more than your standard ported or sealed box.
3) The 10W7 is not compatible with his amplifier. The amp puts out 1000w at 1 ohm, 500w at 2 ohms. The W7 has a single 3-ohm Voice Coil, meaning that he would only be sending it around 400w. He'd be wasting the amplifier on this sub
My suggestion is to go with a 12" Stereo Integrity Mag D2. These are VERY nice woofers and can be had for $250 and up, cepending on where you look. Do a search on these and you'll see that the Mag is an amazing sub. Many people on here have run them with great success. They have great output and sound quality. You will not be disappointed.