The 8w7 is one expensive mother, which is why I would just get the eD 8a at 145$...it is meant to be very close to what the 8w7 is. eD looks up to JL and their quality products, but try to make something different, to an extent, with similar values.
With the 8w7-3 (3 ohm) you can probably get around 300W RMS, I believe. That'll be right at its thermal limit according to JL, who recommend the 250/1 for the 8w7-3.
The eD 8a is rated to do 350W continuous in a .25 cube sealed box. So again...the 250/1 is a good match. Hell, if you want it to hit real hard you can go with a vented box at .5 cubes tuned to 30hz like eD suggests, and it'd probably sound pretty sick. The only issue I can see is that it's a dual 4 ohm so when it's wired you get a 2 ohm load connected the 250/1, which will toss more power than 300W. You can always turn the gain down a bit, of course...
I would toss in Adire Audio and Resonant Engineering's names here, but I don't believe that they make an 8" sub of this quality/level.